Lightly grease a 9x13-inch baking dish with nonstick spray or butter. For cleaner slices, line the bottom with parchment paper, leaving some overhang on the sides to lift the bars out later.
nonstick cooking spray or butter, parchment paper
In a medium bowl, combine the graham cracker crumbs, granulated sugar, and 1/2 teaspoon ground cinnamon. Pour in the melted butter and mix until the crumbs are evenly moistened and the mixture resembles wet sand.
2 cups graham cracker crumbs, 1/4 cup granulated sugar, 1/2 teaspoon ground cinnamon, 1/2 cup unsalted butter
Press the crumb mixture firmly and evenly into the bottom of the prepared pan using the bottom of a measuring cup or glass. For a no-bake version, refrigerate the crust for at least 30 minutes while you prepare the layers. For a slightly firmer crust, bake at 350°F (175°C) for 8–10 minutes, then cool completely before adding the cream cheese layer.
In a mixing bowl, beat the softened cream cheese with a hand mixer until very smooth, about 1–2 minutes. Add 1 cup powdered sugar and 1 teaspoon vanilla extract, then beat again until fluffy and completely smooth with no lumps.
8 ounces cream cheese, 1 cup powdered sugar, 2 teaspoons pure vanilla extract
Gently fold 1 cup of the whipped topping into the cream cheese mixture with a spatula until fully combined. Carefully spread this cream cheese layer over the cooled or well-chilled crust, going slowly so you don’t pull up the crust. Chill in the refrigerator while you prepare the pumpkin layer (10–15 minutes helps it firm up).
3 1/2-4 cups whipped topping
In a large bowl, whisk together the instant vanilla pudding mixes and cold milk for about 2 minutes, until the mixture starts to thicken. Whisk in the pumpkin puree, brown sugar, 1 1/2 teaspoons cinnamon, nutmeg, ginger, cloves (if using), and the remaining 1 teaspoon vanilla extract until smooth and fully combined. The mixture should be thick but spreadable.
1 can pure pumpkin puree, 2 boxes instant vanilla pudding mix, 2 1/2 cups whole milk, 1/2 cup brown sugar, 1 1/2 teaspoons ground cinnamon, 1/2 teaspoon ground nutmeg, 1/2 teaspoon ground ginger, 1/4 teaspoon ground cloves, 2 teaspoons pure vanilla extract
Carefully spoon the pumpkin pudding mixture over the chilled cream cheese layer. Gently spread it all the way to the edges in an even layer, trying not to disturb the cream cheese layer underneath. If the pumpkin mixture seems too loose, let it sit a few minutes in the bowl to thicken before spreading.
Gently spread 2 1/2–3 cups of whipped topping over the pumpkin layer, using light strokes so the layers stay distinct and don’t mix together. Smooth the top as desired.
3 1/2-4 cups whipped topping
Cover the pan tightly with plastic wrap or foil and refrigerate for at least 4 hours, or overnight if possible. This chilling time allows the layers to set and makes for cleaner slices.
Just before serving, dust the top with ground cinnamon or pumpkin pie spice. Garnish with crushed graham crackers, chopped pecans, or a drizzle of caramel sauce if desired. Cut into 15–18 squares with a sharp knife, wiping the blade between cuts for neat edges, and serve chilled.
ground cinnamon or pumpkin pie spice, crushed graham crackers, chopped pecans, caramel sauce