First, preheat your oven to 350 degrees Fahrenheit (175 degrees Celsius). Grease and flour three 8-inch round cake pans.

In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.

In a large mixing bowl, cream together the softened butter and sugar until light and fluffy. Add the eggs one at a time, beating well after each addition. Stir in the vanilla extract.

Gradually add the dry ingredients to the butter mixture, alternating with the milk. Begin and end with the dry ingredients, mixing until just combined.

Divide the cake batter evenly among the prepared cake pans. Smooth the tops with a spatula.

Bake in the preheated oven for 25 to 30 minutes, or until a toothpick inserted into the center comes out clean.

Remove the cakes from the oven. Allow them to cool in the pans for 10 minutes. Then, transfer them to a wire rack to cool completely.

To make the cookie dough filling, first heat treat the flour. Bake the flour on a baking pan for 5 minutes at 350 degrees Fahrenheit.

Then, in a large mixing bowl, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy. Add the milk and vanilla and mix well.

Gradually add the flour and salt to the butter mixture, mixing until well combined. Stir in the mini chocolate chips.

Place one cake layer on a serving plate. Spread a generous amount of cookie dough filling evenly on top. Repeat with the remaining cake layers and filling.

Then, make the frosting. In a separate bowl, beat the softened butter until creamy. Gradually add the powdered sugar, alternating with the heavy cream, until the desired consistency is reached. Stir in the vanilla.

Frost the top and sides of the cake with the buttercream frosting.

Garnish the cake with mini chocolate chips, pressing them gently onto the sides of the cake.

Refrigerate the cake for at least 1 hour to allow the flavors to meld together.

Finally, slice and serve this cookie dough cake!