This one is a showstopper — beautiful and delicious! It has the best of both worlds — edible cookie dough and soft-baked cookies, plus frosting.
Technique tip: Line the cake pans with plastic wrap before pressing the cookie dough down; it will it super easy to remove. The freezer is your friend, so use it to chill your different layers to speed up the process. Get down to eye level when you are building the cake to make sure each layer is completely level before you add the next piece.
Swap option: You could use any edible cookie dough for the cookie dough layers. Don't want to make the icing from scratch? You could always buy frosting from the store if you're in a time crunch. Have fun decorating the top: Elevate it by adding fresh flowers, candles or a cute sign.
For the cookie butter:
Place the cookies in a food processor. Pulse until you achieve uniform crumbs. You may need to remove the lid and stir a few times to make sure the cookies crumble evenly. Turn the processor on low and slowly add the oil until the mixture has a spreadable consistency, like peanut butter. Pulse a few additional times. Use a rubber spatula to scrape the cookie butter from the food processor into an airtight container. Set aside.
For the cookie dough:1.
In a medium bowl, whisk together the heat-treated flour, cornstarch, cream of tartar, baking soda, baking powder and salt. Set aside.2.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium speed until smooth and creamy, about 2 minutes. Add the sugar and mix on medium until light and fluffy, about 4 minutes. Use a rubber spatula to scrape the bowl. Add the egg whites and vanilla and mix until fully incorporated, about 2 minutes.3.
Add half of the flour mixture and mix on low just until the powdery texture of the flour disappears, about 15 seconds. Immediately add the rest of the flour mixture and mix until combined. Scrape the bowl and mix a final 15 seconds.4.
Remove the bowl from the mixer and use a rubber spatula to fold in the white chips. Drop the animal cookie butter in tablespoon-size scoops in four different locations in the bowl. Use the rubber spatula to gently swirl until you see thick ribbons of animal cookie butter.5.
Chill the dough in the freezer for 15 minutes, or until it is easy to handle.6.
Meanwhile, line a 9-inch cake pan with plastic wrap. Divide the dough in half. Press half of the dough into the cake pan in a flat, even layer. Cover with plastic wrap. Freeze for 10 minutes, then pop the layer out of the pan. Cover and stick it back in the fridge. Repeat with the second half of the cookie dough. Set both layers aside in the fridge.
For the cookie layers:1.
Preheat the oven to 350 F.2.
In a medium bowl, whisk together the heat-treated flour, cornstarch and salt. Set aside.3.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter on medium speed until smooth and creamy, about 2 minutes. Add the granulated and brown sugars and mix on medium until light and fluffy, about 4 minutes. Use a rubber spatula to scrape the bowl. Add the egg whites and vanilla, and mix until fully incorporated, about 2 minutes.4.
Add half of the flour mixture and mix on low just until the powdery texture of the flour disappears, about 15 seconds. Immediately add the rest of the flour mixture and mix until combined. Scrape the bowl and mix a final 15 seconds.5.
Remove the bowl from the mixer and use a rubber spatula to fold in the sprinkles, semisweet chips and white chips.6.
Line the bottom of three 9-inch cake pans with parchment paper, then spray the parchment and pan sides with cooking spray. Divide the dough into 3 equal portions and spread each portion evenly into the greased pan. If you don't have 3 cake pans, do these one at a time.7.
Bake for 30-40 minutes, until the cookie layers look set with a light golden-brown edge. Remove from the oven and allow the cakes to cool completely in the pan — this will take several hours. You can speed it up by letting them cool in the fridge.
For the buttercream:
In the bowl of a stand mixer fitted with the paddle attachment, whip the butter until very smooth and creamy. Add half of the powdered sugar and mix on low just until combined. Add the rest of the powdered sugar, the cream and vanilla. Slowly turn the mixer up to medium and whip until very fluffy, about 5 minutes. Make sure the buttercream is a spreadable consistency; if it's too thick, add a teaspoon of cream. Transfer to piping bags.
Remove the cookie dough layers from the refrigerator. Use an 8-inch cake cutter to cut out each layer. Take the excess cookie dough and roll it into tablespoon-size balls. Roll in sprinkles and set aside.2.
Use an 8-inch cake cutter to cut completely cooled baked cookie cake layers. Place the outside crust in a medium bowl and use a wooden spoon or your hands to break the excess cookie into crumbs. Set aside.3.
Place a baked layer on a turntable or cake plate. Pipe a single layer of buttercream onto the cookie layer, smooth with an offset spatula (rubber works too!) and top with a cookie dough layer. Repeat with the remaining layers, alternating baked and unbaked. Once you've piped and smoothed buttercream onto the top of the final baked layer, sprinkle it with cookie crumbs. In a pattern along the outside rim of the cake, arrange the cookie dough balls and use dollops of buttercream to keep them in place.4.
Chill in the fridge until ready to serve. Use a warm knife and cut directly down to slice and serve. Store the cake covered in the refrigerator for up to 2 days.