Step 1

Preheat the oven to 350 degrees and line your 9x13-inch baking pan (see note below) with parchment paper and non-stick spray.

Step 2

Whisk together the flour, baking powder, baking soda, and salt in a medium-sized bowl. Set aside.

Step 3

In the bowl of an electric stand mixer using the paddle attachment, beat together the butter and sugar on medium-high speed until creamy (about 1-2 minutes). Beat in the eggs, one at a time on medium speed, until combined. Then mix in the vanilla. Scrape down the sides and bottom of the bowl a few times as needed.

Step 4

On low speed, alternate between adding the flour mixture and the milk, starting and ending with the flour (add about half of the flour mixture, then the milk, then the rest of the flour). Mix just until each one is combined before adding the next.

Step 5

Take the bowl off of the stand and gently fold in the mini chocolate chips with a silicone spatula. Scrape the cake batter into the prepared pan and smooth it out into an even layer (the cake batter will be on the thicker side). Bake for 28-32-minutes, or until a toothpick inserted into the middle comes out clean. Allow the cake to completely cool before frosting.

Step 6

Preheat the oven to 350 degrees and evenly pour flour onto a baking sheet. Bake the flour for 5 minutes and allow it to cool completely on the counter before using.

Step 7

In the bowl of an electric stand mixer using the paddle attachent, cream together the butter, brown sugar, and sugar until smooth (about 1-2 minutes). Add a 1/4 cup of heavy cream and the vanilla and beat on medium-high speed for 2-3 minutes (we want the buttercream to be really light and creamy).

Step 8

On low speed, mix in the flour, mini chocolate chips, and 1 tbsp of heavy cream. Then whip on medium-high speed for another minute.

Step 9

Frost the cooled cake (you can either do this in the pan or remove the cake first), slice, and serve. Keep any leftover cake slices in an airtight container and store them in the refrigerator for up to 5 days.