Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing them.

In a large mixing bowl, cream together 1.5 cups of softened butter and 2.25 cups of granulated sugar until fluffy.

Add 4 large eggs one at a time and 1 Tbsp of vanilla extract, mixing until smooth.

In a separate bowl, whisk together 3 cups of all-purpose flour, 0.25 cups of cornstarch, 2 tsp of baking powder, and 1 tsp of kosher salt.

Gradually add dry ingredients to the wet mixture, alternating with 1.25 cups of milk, mixing on low speed.

Fold in 1 cup of mini chocolate chips and 9 crushed Chips Ahoy cookies.

Divide the batter between the prepared cake pans and smooth the tops.

Bake for 25-30 minutes, checking for doneness with a toothpick.

Allow the cakes to cool in the pans for 10 minutes before transferring to wire racks.

Beat together ingredients for frosting until smooth and creamy.

Frost one layer, add the second layer on top, and frost the sides and top of the cake.