Cosmic Brownies Copycat Recipe (Nostalgic, Fudgy & Fun)
If you grew up loving those glossy, chewy Little Debbie treats, this Cosmic Brownies Copycat Recipe brings all that childhood magic home—extra fudgy, rich with chocolate, and loaded with rainbow sprinkles.
These homemade cosmic brownies are my love letter to every packed school lunch from the ’80s and ’90s. They’ve got a dense, chewy chocolate brownie base, a silky brownie ganache frosting on top, and a playful scattering of rainbow candy sprinkles (or candy-coated chocolate chips) that make them look like a party on a plate.
I like to bake a pan on Sunday, cut them into tidy bars, and stash them in the fridge. They’re perfect for after-school snacks, bake sales, or honestly, a little midnight nibble when the house is quiet.
Let me walk you through how to make bakery style brownies from scratch that taste like a grown-up version of the classic cosmic snack cake—only richer, fresher, and way more satisfying.
Why You’ll Love This Cosmic Brownies Copycat Recipe
- Ultra-fudgy texture – These chewy chocolate brownie bars are dense and rich, not cakey or dry.
- True copycat flavor – Deep cocoa taste, soft set ganache, and bright sprinkles just like the Little Debbie brownies you remember.
- No mixer needed – Everything comes together in one bowl with a whisk and spatula.
- Budget-friendly treat – A whole 9×13 pan of homemade cosmic brownies costs less than a couple of boxes at the store.
- Freezer-friendly – They freeze beautifully, so you can have a rich chocolate dessert on hand anytime.
- Perfect for kids and grown-ups – Nostalgia for you, rainbow magic for them.
- Customizable toppings – Change up the sprinkles, drizzle peanut butter, or add nuts for your favorite twist.
- Great for parties and potlucks – They slice cleanly into neat bars and travel well in lunch boxes and trays.
Ingredients
For this Cosmic Brownies Copycat Recipe, you’ll need pantry staples plus a few fun toppings. Using good-quality cocoa and chocolate really takes these homemade cosmic brownies up a notch.
For the fudgy chocolate brownies:
- 1 cup (2 sticks / 226 g) unsalted butter, melted and slightly cooled
(Use real butter, not margarine, for the richest flavor.) - 1 ½ cups (300 g) granulated sugar
- ½ cup (100 g) packed light brown sugar
(Brown sugar adds moisture and that chewy candy-bar texture.) - 3 large eggs, room temperature
- 2 large egg yolks, room temperature
(Extra yolks boost fudginess.) - 2 teaspoons pure vanilla extract
- 1 cup (120 g) unsweetened cocoa powder
(Dutch-process if you like a deeper chocolate flavor.) - 1 cup (125 g) all-purpose flour, spooned and leveled
- 2 tablespoons cornstarch
(Helps keep the brownies soft and tender.) - ½ teaspoon baking powder
- ¾ teaspoon fine sea salt
For the brownie ganache frosting:
- 1 ½ cups (255 g) semi-sweet chocolate chips
(You can use dark chocolate chips if you like a less-sweet ganache.) - ¾ cup (180 ml) heavy cream
- 2 tablespoons unsalted butter, softened
(Makes the ganache smooth and glossy.) - 1 teaspoon vanilla extract
- Pinch of salt
For the “cosmic” topping:
- ½–¾ cup rainbow candy-coated chocolate chips or rainbow candy sprinkles
(Look for “rainbow chip sprinkles” or mini rainbow chocolate chips; regular jimmies also work.)
You know what? If you’re baking a lot, this is a nice time to check your cocoa dates and your sprinkles stash. Old cocoa gets flat and dusty, and sad sprinkles don’t bring much joy.
Directions
1. Prep your pan and oven.
Preheat your oven to 325°F (163°C). Line a 9×13-inch metal baking pan with parchment paper, leaving overhang on the long sides for easy lifting. Lightly spray the parchment and sides with nonstick spray.
Tip: A metal pan helps these from scratch brownies bake evenly and stay chewy; glass tends to overbake the edges.
2. Melt the butter and mix in the sugars.
In a large, heat-safe bowl, melt the butter (microwave or stovetop). Let it cool for 3–4 minutes so it’s warm, not hot. Whisk in the granulated sugar and brown sugar until the mixture looks glossy and thick.
3. Add eggs, yolks, and vanilla.
Whisk in the 3 eggs, 2 egg yolks, and vanilla extract. Stir for a full 30–45 seconds; this helps the sugar dissolve and gives you that shiny, crinkly top we all love.
4. Sift in the dry ingredients.
Place a fine-mesh sieve over the bowl and sift in the cocoa powder, flour, cornstarch, baking powder, and salt. This step breaks up cocoa clumps and keeps your batter smooth.
5. Fold gently—don’t overmix.
Using a spatula, fold the dry ingredients into the wet just until no dry patches remain. The batter will be thick and dark. Overmixing adds extra air and makes the brownies more cakey, so stop as soon as everything is combined.
6. Spread into the pan.
Scrape the batter into your prepared pan and smooth the top with an offset spatula or the back of a spoon. Try to nudge the batter into the corners so the brownies bake evenly.
7. Bake low and slow.
Bake at 325°F for 22–28 minutes. Start checking at 22 minutes. The edges should look set and slightly pulled away from the pan, and a toothpick inserted near the center should come out with moist, fudgy crumbs but not wet batter.
If you like very fudgy chocolate brownies, lean toward the shorter bake time—remember they’ll firm up as they cool.
8. Cool completely before topping.
Set the pan on a cooling rack and let the brownies cool completely, at least 1–1½ hours. You can pop them in the fridge for 30 minutes to speed things up. If the brownies are warm, the ganache will slide off and soak in too much.
9. Make the brownie ganache frosting.
Place the chocolate chips and butter in a medium heat-safe bowl. Heat the heavy cream in a small saucepan (or microwave-safe measuring cup) until it’s steaming and just beginning to bubble around the edges—don’t let it boil. Pour the hot cream over the chocolate and let sit for 2–3 minutes, then add vanilla and a pinch of salt and whisk gently until smooth and shiny.
10. Pour and spread the ganache.
Pour the ganache over the cooled brownies and use an offset spatula to spread it into an even layer. Move fairly quickly; the ganache will thicken as it cools.
11. Add the “cosmic” sprinkles.
While the ganache is still soft and glossy, scatter your rainbow candy sprinkles or rainbow chocolate chips evenly across the top. Press them very lightly with your palm so they stick but don’t sink.
12. Chill for clean cuts.
Refrigerate the brownies for at least 1 hour, or until the ganache is set and sliceable. Use the parchment overhang to lift the whole slab out of the pan, place it on a cutting board, and cut into 18–24 bars with a sharp knife. Wipe the knife between cuts for those bakery-style brownie edges.
Servings & Timing
- Yield: 18–24 cosmic brownies, depending on how big you slice them
- Prep Time: About 20 minutes
- Bake Time: 22–28 minutes
- Cooling & Chilling Time: About 2 hours (cooling + ganache setting)
- Total Time: Around 2 hours 45 minutes, most of it hands-off
I know that sounds long, but most of the time you’re just waiting. The actual “hands in the batter” part is pretty quick.
Variations
You can have a lot of fun with this Cosmic Brownies Copycat Recipe—here are a few ideas if you’re feeling playful:
- Peanut Butter Swirl Cosmic Brownies – Swirl ¼ cup warmed peanut butter into the brownie batter before baking, and drizzle a little on top of the ganache.
- Mint Chocolate Cosmic Brownies – Add ½ teaspoon peppermint extract to the ganache and top with crushed mint candies instead of sprinkles.
- Gluten-Friendly Version – Use a 1:1 gluten-free all-purpose flour blend in place of regular flour; keep the cornstarch as written.
- Extra Dark Brownies – Use dark cocoa powder and bittersweet chocolate chips for a less-sweet, more intense chocolate dessert.
- Nutty Cosmic Brownies – Fold ½ cup chopped toasted walnuts or pecans into the batter for crunch.
- Holiday Cosmic Bars – Swap rainbow sprinkles for seasonal colors (red and green for Christmas, pastel for Easter, orange and black for Halloween).
Storage & Reheating
One of the perks of these chewy chocolate brownie bars is how well they keep.
- Room Temperature: Store sliced brownies in an airtight container at room temperature for up to 2 days. If your kitchen is warm, the ganache can get soft and smudgy.
- Refrigerator: For the neatest cuts and best copycat little debbie brownies texture, keep them in the fridge for up to 5–6 days. They’re extra chewy cold and soften a little as they sit at room temp.
- Freezer: Wrap individual brownies tightly in plastic wrap, then place in a freezer-safe bag or container. Freeze for up to 2 months. Thaw in the fridge or at room temperature for about 30 minutes.
There’s no real “reheating” here—these taste best cool or at room temp. If you like a slightly softer ganache, let a chilled brownie sit out for 10–15 minutes before serving.
Make-ahead tip: Bake the brownies the day before, keep them chilled, and slice the next morning. They actually slice better after a night in the fridge.
Notes
- Don’t overbake. If your homemade cosmic brownies seem dry or cakey, they probably baked a few minutes too long. Pull them as soon as the center is set and no longer jiggly.
- Use room-temperature eggs. Cold eggs can seize the melted butter and lead to a thicker, harder-to-mix batter, which can affect texture.
- Cocoa quality matters. I tested these with both store-brand cocoa and Ghirardelli; the higher-quality cocoa gave a deeper, smoother flavor that really reminded me of a rich chocolate dessert, not just a snack cake.
- Ganache thickness. If your ganache seems too thin, let it sit at room temp for 10–15 minutes and whisk again. It naturally thickens as it cools.
- Smaller bars for kids. I like to cut smaller, lunchbox-friendly pieces for kids (24 bars) and slightly larger ones for parties (18 bars).
- Line the pan well. That parchment sling is your friend—these brownies are so fudgy that they cling to unlined pans.
I’ve baked these for everything from school fundraisers to my husband’s office party, and they’re usually the first thing gone. Grown men in suits have asked me where I “bought those brownies with the little rainbow chips.” That’s always my favorite compliment.
FAQs
Can I make this Cosmic Brownies Copycat Recipe without heavy cream?
You can use full-fat canned coconut milk in place of heavy cream for the ganache; it changes the flavor slightly, but the texture is still smooth and rich.
Do I have to use both granulated and brown sugar?
You don’t have to, but the mix of sugars adds chewiness and moisture—using only white sugar will make the brownies a bit drier and less soft.
Can I use cocoa mix instead of cocoa powder?
No, cocoa mix has sugar and other ingredients that throw off the recipe; stick with unsweetened cocoa powder for this fudgy chocolate brownie base.
My ganache looks grainy. What happened?
Usually the cream was too hot or the chocolate overheated. Let it cool slightly, then whisk in a tablespoon or two of extra warm cream to smooth it out.
Can I bake these in an 8×8 pan instead?
You can, but the brownies will be very thick and may need 10–15 extra minutes in the oven; keep an eye on the center and test often.
How do I get super clean slices like bakery style brownies?
Chill the brownies until firm, use a long sharp knife, and wipe the blade with a warm, damp cloth between each cut.
Are these brownies very sweet?
They are sweet like the original cosmic brownies, but using semi-sweet chocolate (instead of milk chocolate) in the ganache keeps them from being too sugary.
Can I skip the sprinkles?
Of course, though that’s the “cosmic” part; you’ll still have a beautiful, glossy ganache-topped brownie if you want something a little more grown-up.
Conclusion
This Cosmic Brownies Copycat Recipe brings that familiar Little Debbie nostalgia right to your kitchen—only with richer chocolate flavor, a silkier ganache, and a chewy, from scratch brownie base that feels special enough for any celebration. It’s simple, fun, and very forgiving, even if you don’t bake every week.
If you try these homemade cosmic brownies, I’d love to hear how they turned out for you—tell me in the comments how fast they disappeared, or what toppings you used. And if you’re in a brownie mood, you might enjoy my other chocolate-heavy treats next, like peanut butter swirl brownies or classic one-bowl fudge brownies.
Cosmic Brownies Copycat Recipe (Nostalgic, Fudgy & Fun)
Ingredients
- 1 cup unsalted butter 2 sticks / 226 g, melted and slightly cooled; use real butter, not margarine
- 1 1/2 cups granulated sugar
- 1/2 cup light brown sugar packed (100 g)
- 3 large eggs room temperature
- 2 large egg yolks room temperature; extra yolks boost fudginess
- 2 teaspoons vanilla extract pure
- 1 cup unsweetened cocoa powder 120 g; Dutch-process optional for deeper chocolate flavor
- 1 cup all-purpose flour 125 g, spooned and leveled
- 2 tablespoons cornstarch keeps brownies soft and tender
- 1/2 teaspoon baking powder
- 3/4 teaspoon fine sea salt
- 1 1/2 cups semi-sweet chocolate chips 255 g; or dark chocolate chips for less-sweet ganache
- 3/4 cup heavy cream 180 ml
- 2 tablespoons unsalted butter softened, for ganache
- 1 teaspoon vanilla extract for ganache
- salt pinch, for ganache
- 1/2-3/4 cup rainbow candy-coated chocolate chips or rainbow sprinkles for the “cosmic” topping
- nonstick spray for greasing the pan
- parchment paper to line a 9x13-inch metal baking pan
Instructions
- Preheat your oven to 325°F (163°C). Line a 9x13-inch metal baking pan with parchment paper, leaving overhang on the long sides to form a sling. Lightly spray the parchment and exposed sides of the pan with nonstick spray.nonstick spray, parchment paper
- In a large heat-safe bowl, melt the 1 cup (226 g) unsalted butter using the microwave or stovetop. Let it cool for 3–4 minutes until warm but not hot. Whisk in the granulated sugar and light brown sugar until the mixture looks glossy and thick.1 cup unsalted butter, 1 1/2 cups granulated sugar, 1/2 cup light brown sugar
- Whisk the 3 eggs, 2 egg yolks, and 2 teaspoons vanilla extract into the butter-sugar mixture. Whisk vigorously for 30–45 seconds to help dissolve the sugar and create a shiny, crinkly top on the brownies.3 large eggs, 2 large egg yolks, 2 teaspoons vanilla extract
- Place a fine-mesh sieve over the bowl and sift in the cocoa powder, all-purpose flour, cornstarch, baking powder, and fine sea salt. This helps break up any cocoa clumps and keeps the batter smooth.1 cup unsweetened cocoa powder, 1 cup all-purpose flour, 2 tablespoons cornstarch, 1/2 teaspoon baking powder, 3/4 teaspoon fine sea salt
- Using a spatula, fold the dry ingredients into the wet ingredients just until no dry patches remain. The batter will be thick and dark. Avoid overmixing so the brownies stay dense and fudgy rather than cakey.
- Scrape the brownie batter into the prepared pan and smooth the top with an offset spatula or the back of a spoon, nudging the batter into the corners for even baking.
- Bake at 325°F (163°C) for 22–28 minutes. Start checking at 22 minutes. The edges should look set and slightly pulled away from the pan, and a toothpick inserted near the center should come out with moist, fudgy crumbs but no wet batter. For very fudgy brownies, lean toward the shorter bake time.
- Set the pan on a cooling rack and let the brownies cool completely in the pan, at least 1–1 1/2 hours. To speed this up, place the pan in the refrigerator for about 30 minutes. The brownies must be fully cool or the ganache will slide off and soak in too much.
- Place the semi-sweet chocolate chips and 2 tablespoons softened butter in a medium heat-safe bowl. Heat the heavy cream in a small saucepan or microwave-safe cup until steaming and just beginning to bubble around the edges (do not boil). Pour the hot cream over the chocolate and let sit for 2–3 minutes. Add the vanilla extract and a pinch of salt, then whisk gently until smooth, glossy, and fully combined.1 1/2 cups semi-sweet chocolate chips, 3/4 cup heavy cream, 2 tablespoons unsalted butter, 1 teaspoon vanilla extract, salt
- Pour the ganache over the cooled brownies and use an offset spatula to spread it into an even layer. Work fairly quickly, as the ganache will begin to thicken as it cools.
- While the ganache is still soft and glossy, scatter the rainbow candy-coated chocolate chips or rainbow sprinkles evenly over the top. Press them very lightly with your palm so they adhere without sinking.1/2-3/4 cup rainbow candy-coated chocolate chips or rainbow sprinkles
- Refrigerate the pan for at least 1 hour, or until the ganache is set and sliceable. Use the parchment overhang to lift the brownie slab out of the pan onto a cutting board. Cut into 18–24 bars with a sharp knife, wiping the blade clean between cuts for neat, bakery-style edges.
