Millionaire’s Shortbread Recipe (Thick Caramel, Buttery Base & Shiny Chocolate)
If you love rich, buttery desserts, this Millionaire’s Shortbread Recipe is your new showstopper: a crisp shortbread base, thick condensed milk caramel, and a glossy chocolate topping that slices into perfect caramel chocolate squares.
I’ve been making some version of millionaire’s shortbread (also called caramel shortbread bars or chocolate caramel slice) since the late ’90s, back when my kids were still trading snack bars in their lunchboxes. This classic British traybake has stood the test of time in my kitchen. It looks fancy, tastes like it came from a bakery, and yet it’s very doable in a home oven with basic pantry ingredients.
What makes this layered shortbread dessert special is the contrast: a firm, buttery shortbread base, a rich caramel layer that’s thick but sliceable, and a smooth chocolate topping with just the right snap. It’s sweet, yes, but in that “just one more little square” kind of way. I often cut these into tiny pieces for holiday platters, teacher gifts, and potlucks. They travel well, freeze beautifully, and—if I’m honest—almost never come back home.
Let’s get into how you can make your own homemade millionaire bars, with all my notes from years of tweaking the recipe so the caramel doesn’t burn, the chocolate doesn’t crack, and the layers stay neat and gorgeous.
Why You’ll Love This Millionaire’s Shortbread Recipe
- Buttery shortbread base that actually stays crisp under all that caramel
- Thick, rich condensed milk caramel that sets up without being chewy like toffee
- Shiny chocolate topping that slices cleanly (I’ll show you the temperature trick)
- Uses simple pantry ingredients you probably already have on hand
- Great make-ahead dessert—tastes even better the next day
- Freezer-friendly layered shortbread dessert for parties and holidays
- Easy to customize with nuts, flaky salt, or dark vs. milk chocolate
- Impressive “bakery look” with straightforward, step-by-step directions
- Perfect for cookie trays, bake sales, and lunchbox treats
- Crowd-pleasing classic British traybake that Americans absolutely adore
Ingredients for Millionaire’s Shortbread Recipe
Here’s what you’ll need for the three layers of this traditional millionaire’s slice. I’ve included a few notes and substitutions from my own kitchen testing.
Shortbread Base
- 1 cup (2 sticks / 226 g) unsalted butter, softened
- 1/2 cup (100 g) granulated sugar
- 2 1/4 cups (270 g) all-purpose flour, spooned and leveled
- 1/4 teaspoon fine sea salt (skip if using salted butter)
Notes:
Use real butter here—this is where the flavor starts. If your butter is very cold, cut it into small cubes and let it sit 15–20 minutes.
Caramel Layer
- 1 cup (2 sticks / 226 g) unsalted butter, cut into pieces
- 1 cup (200 g) light brown sugar, packed
- 2 cans (14 oz / 397 g each) sweetened condensed milk
- 1/4 cup (60 ml) light corn syrup (helps prevent grainy caramel)
- 1 teaspoon pure vanilla extract
- 1/2 teaspoon fine sea salt
This is your rich caramel shortbread center. The condensed milk caramel is what gives that smooth, fudge-like texture instead of a hard toffee.
Chocolate Topping
- 2 cups (340 g) semi-sweet chocolate chips or chopped bar chocolate
- 2 tablespoons unsalted butter OR heavy cream (for a softer bite)
- Optional: flaky sea salt (like Maldon) for sprinkling on top
Chocolate tip:
Use a mix of semi-sweet and a little milk chocolate if you prefer a sweeter chocolate topped shortbread. If you like a darker, more grown-up flavor, go with 60–70% dark chocolate.
Step-by-Step Directions
You’ll need a 9×13-inch metal baking pan, parchment paper, and a medium heavy-bottomed saucepan. A silicone spatula is very handy here.
1. Prep Your Pan and Oven
- Line a 9×13-inch pan with parchment paper, leaving some overhang on the long sides so you can lift the bars out later.
- Lightly spray or butter the parchment and sides of the pan.
- Preheat your oven to 325°F (165°C).
This helps your buttery shortbread base bake evenly without sticking.
2. Make the Shortbread Base
-
In a large mixing bowl (or stand mixer), cream together the softened butter and granulated sugar until pale and fluffy, about 2–3 minutes.
-
Add the flour and salt, and mix on low just until the dough starts to come together and looks like slightly clumpy sand. It should hold when you press it between your fingers.
-
Tip the mixture into your prepared pan. Press it down firmly and evenly with clean hands or the bottom of a measuring cup, making sure to get into the corners.
-
Use a fork to poke a few holes across the surface—this keeps the shortbread from puffing too much.
-
Bake for 22–25 minutes, or until the edges are just turning light golden and the top looks set.
Set aside on a rack to cool slightly while you start the caramel. The base can be warm when you pour the caramel over it, just not piping hot.
3. Cook the Caramel Layer
This is the heart of your millionaire’s shortbread recipe, so stay close to the stove.
-
In a medium heavy saucepan, combine butter, brown sugar, sweetened condensed milk, and corn syrup.
-
Cook over medium heat, stirring constantly with a silicone spatula or wooden spoon, until the butter melts and everything comes together.
-
Once the mixture starts to bubble, reduce heat to medium-low. Keep stirring—get into the corners of the pot so nothing sticks.
-
Continue to cook and stir for 8–12 minutes, until the caramel thickens and turns a deeper golden color. It should leave a trail when you drag the spatula through it, and bubbles will become slower and more lava-like.
If you have a candy thermometer, you’re aiming for around **225–230°F (107–110°C)**—this keeps the caramel thick but sliceable, not chewy like a hard caramel candy.
- Remove from heat and stir in the vanilla and salt.
4. Pour and Set the Caramel
-
Immediately pour the hot caramel over the warm shortbread base.
-
Tilt the pan gently and use a spatula to spread it into an even layer.
-
Let it sit at room temperature for about 30–40 minutes, until the caramel has firmed up a bit and is no longer very hot. You don’t want to add chocolate to steaming caramel, or the layers can separate later.
You can speed this up by popping the pan into the fridge for 20–30 minutes, but don’t freeze at this stage.
5. Add the Chocolate Topping
- Place the chocolate and butter (or cream) in a heatproof bowl.
- Melt in the microwave in 20–30 second bursts, stirring well between each. Or use a double boiler on the stove.
You want smooth, glossy chocolate. Stir well after it’s mostly melted; the residual heat will melt any last bits.
-
When the caramel is set but still ever so slightly warm, pour the melted chocolate over the top.
-
Gently tilt and use an offset spatula to nudge the chocolate into an even layer.
-
If you like a little salt with your sweet, sprinkle flaky sea salt lightly over the surface while the chocolate is still wet.
6. Chill and Slice Cleanly
- Chill the pan in the fridge for about 1–1.5 hours, until the chocolate is set but not rock hard.
Here’s the key: for clean-cut millionaire’s shortbread, don’t slice it straight from the fridge when the chocolate is very cold. It will crack.
- Once chilled, let the pan sit at room temperature for 15–20 minutes.
- Use the parchment overhang to lift the whole slab out onto a cutting board.
- Warm a sharp knife under hot water, dry it, then press straight down to cut into bars or squares, wiping the blade between cuts.
Servings & Timing
- Yield: About 24–32 bars, depending on how large you cut them
- Prep Time: 25–30 minutes
- Cook Time: 30–35 minutes (shortbread + caramel)
- Chill/Set Time: 1.5–2 hours
- Total Time: Around 2.5–3 hours (mostly hands-off chilling time)
For parties, I like cutting these millionaire bars into small, almost bite-size caramel chocolate squares. People feel less guilty taking “just one more” that way.
Variations on This Classic Millionaire’s Shortbread
You know what? This base recipe is wonderful as is, but here are some fun twists:
- Salted Millionaire’s Shortbread: Add 1 teaspoon flaky salt into the caramel and more on top for a sweet-salty contrast.
- Nutty Caramel Shortbread Bars: Sprinkle toasted chopped pecans, almonds, or hazelnuts over the caramel before adding chocolate.
- Dark Chocolate Millionaire Bars: Use 70% dark chocolate for a less sweet, more sophisticated chocolate caramel slice.
- Espresso Millionaire’s Slice: Stir 1–2 teaspoons instant espresso powder into the caramel for a subtle coffee note.
- Peanut Butter Swirl: Swirl a few spoonfuls of warmed peanut butter into the chocolate layer.
- Gluten-Free Version: Use a trusted 1:1 gluten-free baking flour in the shortbread; several of my readers have had success with Bob’s Red Mill.
Storage & Reheating (Plus Make-Ahead Tips)
These rich caramel shortbread bars are very make-ahead friendly, which is one reason I lean on them for busy holiday weeks.
- Room Temperature: In a cool kitchen, they keep well in an airtight container for 2–3 days.
- Refrigerator: For longer storage, keep them in a container in the fridge for up to 1 week. Place parchment between layers so the chocolate doesn’t smudge.
- Freezer: Freeze cut bars on a baking sheet until firm, then transfer to a freezer container or bag for up to 2 months. Thaw in the fridge overnight or on the counter for 30–45 minutes.
No real reheating needed—just bring them closer to room temperature before serving so the caramel and chocolate soften slightly. Straight-from-the-fridge bars will be firmer and a little more “snappy”; room temp gives you that classic soft bite.
Notes from My Kitchen (What I Learned Testing This Recipe)
- Don’t rush the caramel. If you turn the heat too high, it can scorch on the bottom before it thickens. Medium-low and patience give you that smooth condensed milk caramel.
- Use a heavy pan. A thin saucepan will give you hot spots and can burn the sugar. My trusty old All-Clad gets a workout with this recipe.
- Shortbread color matters. Pull the base as soon as the edges begin to turn light golden. Too pale and it can taste floury; too dark and the whole traybake tastes a bit bitter.
- Slice temperature is everything. This is my most common reader question. If the chocolate cracks, you probably cut it when it was too cold. If it smears, it was too warm. Aim for that “slightly cool but not cold” window.
- Use real vanilla and butter. This recipe doesn’t have a lot of extra flavorings, so those basics really shine.
- Half batch friendly. You can halve the recipe and bake it in an 8×8 or 9×9 pan—just keep an eye on bake time and caramel thickness.
Honestly, once you’ve made this millionaire’s shortbread recipe once or twice, it becomes a trusty old friend in your baking rotation.
Millionaire’s Shortbread Recipe FAQs
Can I make millionaire’s shortbread the day before serving?
Yes—this is actually ideal. The layers settle and slice more cleanly the next day.
Why did my caramel turn grainy or crystallized?
This usually means the sugar cooked too fast or wasn’t stirred evenly; keep the heat moderate and stir constantly, scraping the bottom and sides.
My chocolate cracked when I cut the bars. What happened?
The chocolate was too cold and hard. Let the tray sit at room temperature for 15–20 minutes, then use a warm, sharp knife.
Can I use evaporated milk instead of sweetened condensed milk?
No, evaporated milk isn’t sweet or thick enough; you need sweetened condensed milk for that rich, thick caramel layer.
How do I make these less sweet?
Use dark chocolate (60–70%), add a little extra salt to the caramel, and cut the bars into smaller pieces so people can enjoy a richer bite.
Can I use margarine instead of butter?
I don’t recommend it. The buttery flavor is key here, and margarine often has more water, which can change the shortbread texture.
Do these millionaire bars travel well for gifts or potlucks?
They do. Keep them in a single layer or with parchment between layers, store cool, and slice at your destination if you’re worried about heat.
Is this the same as a caramel slice or chocolate caramel slice?
Yes—different countries call this classic traybake by different names, but they all point to that buttery shortbread, thick caramel, and chocolate combo.
Final Thoughts (And a Little Nudge to Bake)
This Millionaire’s Shortbread Recipe has seen my kids through bake sales, my neighbors through new babies, and more holiday cookie trays than I can count. It’s one of those decadent dessert bars that looks fancy but feels comforting and familiar at the same time.
If you give this classic millionaire’s shortbread a try, I’d love to hear how it goes—tell me if you went dark chocolate, added nuts, or sprinkled on the flaky salt. And if you enjoy layered desserts, you might also like playing around with lemon bars, brownies, or other caramel shortbread bars next.
Millionaire’s Shortbread Recipe (Thick Caramel, Buttery Base & Shiny Chocolate)
Ingredients
- 1 cup unsalted butter softened; for shortbread base (2 sticks / 226 g)
- 1/2 cup granulated sugar 100 g
- 2 1/4 cups all-purpose flour 270 g, spooned and leveled
- 1/4 teaspoon fine sea salt skip if using salted butter; for shortbread base
- 1 cup unsalted butter cut into pieces; for caramel layer (2 sticks / 226 g)
- 1 cup light brown sugar packed; 200 g
- 2 cans sweetened condensed milk 14 oz / 397 g each
- 1/4 cup light corn syrup 60 ml; helps prevent grainy caramel
- 1 teaspoon pure vanilla extract for caramel
- 1/2 teaspoon fine sea salt for caramel
- 2 cups semi-sweet chocolate chips or chopped bar chocolate; about 340 g
- 2 tablespoons unsalted butter or heavy cream; for chocolate topping, softer bite
- flaky sea salt optional, for sprinkling on top
Instructions
- Line a 9×13-inch metal baking pan with parchment paper, leaving overhang on the long sides for easy removal. Lightly butter or spray the parchment and sides of the pan. Preheat the oven to 325°F (165°C).
- In a large mixing bowl or stand mixer, cream the softened butter and granulated sugar together until pale and fluffy, about 2–3 minutes. Add the flour and salt, and mix on low just until the mixture looks like slightly clumpy sand and holds together when pressed between your fingers.1 cup unsalted butter, 1/2 cup granulated sugar, 2 1/4 cups all-purpose flour, 1/4 teaspoon fine sea salt
- Tip the shortbread mixture into the prepared pan. Press it down firmly and evenly with clean hands or the bottom of a measuring cup, making sure to reach into the corners. Prick the surface a few times with a fork to prevent puffing. Bake for 22–25 minutes, or until the edges are just turning light golden and the top looks set. Cool slightly on a rack while you start the caramel; the base can be warm but not piping hot when you pour the caramel over.
- In a medium heavy-bottomed saucepan, combine the butter, light brown sugar, sweetened condensed milk, and light corn syrup. Cook over medium heat, stirring constantly, until the butter melts and the mixture is smooth and fully combined.1 cup unsalted butter, 1 cup light brown sugar, 2 cans sweetened condensed milk, 1/4 cup light corn syrup
- Once the caramel mixture begins to bubble, reduce the heat to medium-low. Continue cooking, stirring constantly and scraping the bottom and corners of the pan, for 8–12 minutes, until it thickens and turns a deeper golden color. It should leave a trail when you drag a spatula through it and the bubbles will be slower and more lava-like. If using a candy thermometer, aim for 225–230°F (107–110°C) so the caramel sets thick but sliceable, not chewy.
- Remove the saucepan from the heat and stir in the vanilla extract and fine sea salt until evenly combined.1 teaspoon pure vanilla extract, 1/2 teaspoon fine sea salt
- Immediately pour the hot caramel over the warm shortbread base. Tilt the pan gently and use a spatula to spread it into an even layer. Let the pan sit at room temperature for 30–40 minutes, until the caramel has firmed slightly and is no longer very hot. You can chill it in the fridge for 20–30 minutes to speed this up, but do not freeze at this stage.
- Place the chocolate and butter (or heavy cream) in a heatproof bowl. Melt in the microwave in 20–30 second bursts, stirring well between each, or use a double boiler on the stove. Stir until completely smooth and glossy; residual heat will melt any remaining small pieces.2 cups semi-sweet chocolate chips, 2 tablespoons unsalted butter
- When the caramel is set but still just slightly warm, pour the melted chocolate over the top. Gently tilt the pan and use an offset spatula to spread it into an even layer. If desired, sprinkle lightly with flaky sea salt while the chocolate is still wet.flaky sea salt
- Chill the pan in the refrigerator for 1–1.5 hours, until the chocolate is set but not rock hard. Remove from the fridge and let sit at room temperature for 15–20 minutes so the chocolate softens slightly. Use the parchment overhang to lift the whole slab onto a cutting board. Warm a sharp knife under hot water, dry it, then press straight down to cut into bars or squares, wiping the blade between cuts for clean layers.
Notes
- Salted: Stir about 1 teaspoon flaky salt into the caramel and sprinkle more on top.
- Nutty: Sprinkle toasted chopped pecans, almonds, or hazelnuts over the caramel before adding chocolate.
- Dark chocolate: Use 60–70% dark chocolate for a less sweet version.
- Espresso: Stir 1–2 teaspoons instant espresso powder into the caramel for a coffee note.
- Peanut butter swirl: Swirl warmed peanut butter into the chocolate layer before it sets.
- Gluten-free: Use a 1:1 gluten-free baking flour in the shortbread. Storage & make-ahead:
- Room temperature: Store in an airtight container in a cool kitchen for 2–3 days.
- Refrigerator: Store up to 1 week with parchment between layers.
- Freezer: Freeze cut bars on a baking sheet until firm, then transfer to a container or bag for up to 2 months. Thaw in the fridge overnight or at room temperature for 30–45 minutes. Slice temperature is key: if the chocolate cracks, it’s too cold; if it smears, it’s too warm. Aim for slightly cool but not cold before cutting.
