Preheat oven to 350. Grease three 6-Inch cake pans. I like to use parchment paper and spray with coconut oil spray.
In a medium bowl, mix the buttermilk, sour cream, vegetable oil, egg whites, and vanilla. Sift in white cake mix. Fold in mini chocolate chips. It’s important to use mini chocolate chips, regular chocolate chips will sink to the bottom of your cake.
Bake for 25-28 minutes until center is baked. Remove from oven. Let cool in pan for 5 minutes. Then Transfer to wire cooling rack. Let cool another 5 minutes then wrap in plastic wrap twice. Let continue to cool until room temperature.
If assembling in one day, I recommend freezing the cake for 20 minutes. A cool cake is easier to work with than a room temperature cake.
Cream Butter until light and fluffy. (It’s a million times easier if you do this in a stand mixer like a Bosch or Kitchen Aid)
Add cream, salt and vanilla.
Add in sifted powdered sugar 1/2 Cup to 1 Cup at a time or until desired consistency. Once done, use a rubber spatula to press out air bubbles.
In a small glass bowl (I like to use a larger glass measuring cup with the pour spouts), add in chocolate chips and heavy cream. Microwave for 30 seconds then whisk until smooth. Add to a squeeze bottle for ganache drip on cake.
Eggless Cookie Dough
After the cake is finished baking, clean out two cake pans. Press two layers of plastic wrap in opposite directions so it forms an X and has overhang off the sides. This will help you shape the dough to the same size as your cake rounds.
In a stand mixer with the paddle attachment, cream the butter and sugars together until eight and fluffy.
Add in milk and vanilla.
Add in flour, salt and chocolate chips. This dough will be sticky, add in flour as needed.
Roll the dough into tiny balls for the top decor. I did about 8 small balls. Store in a plastic container with lid in the fridge for about 20 minutes before applying to top of cake.
Divide the rest of the dough into two separate balls and press each into the two prepared cake pans. Squish down using the bottom of a cup to make the dough an even 1/4-1/2 inch thick. Refriderage for at least 20 minutes.
On a cake turntable, tape a 6 inch cardboard round to the top of an 8-inch cardboard round. Top with a small amount of buttercream to use for glue.
Place first cake layer and top with the first cookie dough layer. Add about 1 cup of Buttercream. Spread flat with an offset spatula. Add on next layer of cake and repeat with remaining two layers.
Crumb coat the cake, place in fridge to set for about 5 minutes.
Add sprinkle rim on the bottom (or use mini chocolate chips, whatever you want to decorate!) Then add ganache drip.
Place cake in freezer 5 minutes to allow the ganache to firm before adding the buttercream decor (I used a large french tip) and topping with cookie dough balls.