Now you can have your cake and your cookies too! This Neapolitan Chocolate Chip Cookie Cake is made with three layers of thick chocolate chip cookie, and sandwiched with chocolate, vanilla, and strawberry buttercream.
Line three 8-inch cake pans with parchment paper, and spray them with nonstick cooking spray. Preheat the oven to 350 F.
In a large bowl, sift or whisk together the flour, baking soda, baking powder, and salt, and set aside. Combine the butter and sugar in the bowl of a large stand mixer fitted with the paddle attachment. Beat them together on medium speed until light and fluffy. Add the eggs, one at a time, beating well after each addition, then add the vanilla extract.
With the mixer running on low speed, add the dry ingredients and mix until just a few streaks of flour remain. Stop the mixer and finish mixing by hand, using a rubber spatula to scrape the bottom and sides of the bowl well. Add the chocolate chips and stir them in completely.
Divide the dough between the 3 prepared pans—if you want to use a scale to portion them, each pan should get about 20 oz. Bake the cakes for about 22 minutes, until they're golden brown, starting to pull away from the sides of the pan, and a toothpick inserted into the center comes out clean. Cool the cookie cakes on a wire rack until completely cool. They can be made in advance and kept, well-wrapped in plastic, for several days until ready to use.
To Make the Frosting and Assemble:
Place the unsweetened chocolate in a small bowl and microwave it in 30-second increments until melted. Once melted and smooth, set it aside to cool to room temperature.
Place the freeze-dried strawberries in a food processor and process them until they are a fine powder.
Combine the butter, powdered sugar, 1/3 cup milk, vanilla extract, and salt in the large bowl of a stand mixer fitted with a paddle attachment. Beat on low speed until the sugar is moistened, then raise the speed to medium and beat for 2-3 minutes until light and fluffy.
Divide the frosting into three approximately equal portions, making one slightly larger than the other two. (This will be the top layer, which requires more frosting for piping decorations.) Add the melted chocolate and a tablespoon of milk to the second portion, and stir until well-mixed. Add the strawberry powder and the remaining milk to the third portion and stir until well-mixed.
Place one cookie layer on your serving plate, and spread the chocolate frosting on top of the cookie. Add a second cookie on top, and spread the strawberry frosting on the second cookie. Finally, top the stack with the third cookie. Spread some vanilla frosting on top, and use the rest to pipe rosettes or other decorations around the edge. Top with chocolate chips, sprinkles, or mini cookies.
Freeze-dried strawberries can be found at Trader Joe's and many online stores. If you don't have access to them, you can substitute 1/3 cup strained strawberry puree instead. You may want to add a drop or two of pink food coloring to boost the color, and add more powdered sugar if necessary to make the frosting stiffer. This recipe provides a very generous amount of frosting. If you like thinner layers of frosting, or don't want to do decorative piping on top of the cake, you can reduce it by a third.