For the Cake

1. Prepare three 8 inch cake pans with parchment paper circles in the bottom and grease the sides. Preheat oven to 350°F (176°C).
2. Combine the flour, baking powder and salt in a medium sized bowl and set aside.
3. Add the butter, sugars and vanilla extract to a large mixer bowl and beat together on medium speed until light in color and fluffy, about 2-3 minutes. Do not skimp on the creaming time.
4. Add the sour cream and mix until well combined.
5. Add the eggs one at a time, mixing until mostly combined after each. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated.
6. Add half of the dry ingredients to the batter and mix until mostly combined.
7. Slowly add the milk and mix until well combined.
8. Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not over mix the batter.
9. Stir in the mini chocolate chips.
10. Divide the batter evenly between the cakes pans and bake for 22-25 minutes, or until a toothpick comes out with a few crumbs.
11. Remove the cakes from the oven and allow to cool for about 2-3 minutes, then remove to cooling racks to cool completely.

For the Cookie Dough

1. Add the butter, brown sugar and vanilla extract to a large mixer bowl and beat together on medium speed until light in color and fluffy, about 2-3 minutes.
2. Add the salt and flour and mix until well combined, then stir in the mini chocolate chips.
3. Add milk a tablespoon at a time, then combine. You want to add just enough milk so that the cookie dough can be rolled into balls, but remains crumbly.
4. Roll 20 balls of cookie dough that are a 1/2 tablespoon each. Set all the cookie dough aside.

For the Frosting

1. Beat the butter in a large mixer bowl until smooth.
2. Add the brown sugar and vanilla extract and mix until well combined and smooth.
3. Add the flour and salt and mix until well combined and smooth.
4. Add half of the powdered sugar and mix until smooth and well combined.
5. Add 3 tablespoons of cream and mix until smooth and well combined.
6. Add the remaining powdered sugar and mix until well combined and smooth. Add additional water or milk, as needed to get the right consistency of frosting.

For the Assembly

1. Use a large serrated knife to remove the domes from the top of the cakes so that they’re flat. These cakes don’t have a large dome, but I like to make sure they’re completely flat.
2. Place the first cake on a serving plate or a cardboard cake round.
3. Spread about 1 cup of frosting evenly on top of the cake.
4. Crumble up about half of the cookie dough that wasn’t used to make balls and sprinkle it evenly over the frosting. Try to make sure the cookie dough goes all the way to the edges, so you don’t end up with a big gap between the cake layers. Spread a thin layer of frosting on top of the cookie dough, just enough so that the next cake layer has something to stick to.
5. Add the second layer of cake, another cup of frosting and the remaining cookie dough crumbles. Spread another thin layer of frosting on top of the cookie dough.
6. Top the cake with the remaining layer and frost the outside of the cake. Refer to my tutorial for frosting a smooth cake, if needed.
7. Press the mini chocolate chips for the frosting into the sides of the cake.
8. Pipe the remaining frosting around the top edge of the cake and decorate with the cookie dough balls. Use any remaining cookie dough for additional decoration, if desired.
9. Store cake in the fridge, but bring to room temperature before serving. The cookie dough will firm up in the fridge, so you’ll want it to be softer to cut and eat. Cake is best stored well covered in the fridge and should be eaten within 3-4 days.