Step 1

Preheat oven to 350°F. Grease and line three 6 inch cake pans OR two 8-inch cake pans with parchment paper.

Step 2

In a large bowl, whisk together sugar, cocoa powder, flour, baking soda, baking powder, and salt. In a separate bowl, whisk oil, vanilla, eggs, and buttermilk.

Step 3

Pour the wet ingredients into the dry, whisking until no lumps remain. Pour in brewed coffee, mixing until just combined.

Step 4

Pour batter into prepared pans and bake for roughly 30 minutes, or until a knife inserted in the center of the cake comes out clean. Cool completely on a wire rack before frosting.

Step 5

While the cakes cool, make the cookie dough filling. In a stand mixer fit with the paddle attachment beat the butter, brown sugar and granulated sugar together until light and fluffy.

Step 6

Scrape down the bowl and add the pasteurized egg whites and vanilla extract and mix well.

Step 7

Add the flour, salt, and baking soda and mix until combined. Last, add the chocolate chips. Transfer the cookie dough to a separate bowl.

Step 8

Next, make the chocolate buttercream. Place the room temperature butter in a stand mixer fit with the whisk attachment. Beat the butter until creamy. Scrape down the bowl and add the cocoa powder. Beat on low speed and gradually increase to high speed until homogenous.

Step 9

Scrape down the bowl and add the powdered sugar, vanilla extract, espresso powder and 3 Tablespoons of milk to start. Beat on low speed and gradually increase to high speed, beating until light and fluffy.

Step 10

If the frosting feels too stiff, add more milk one tablespoon at a time. If it feels too liquidy, add in 1 tablespoon of powdered sugar at a time until frosting reaches its desired consistency.

Step 11

Frost the cake by placing the first cake layer onto a cake stand. Top with about 1/3 of the cookie dough mixture, patting it into an even layer. Repeat with the second layer and another 1/3 of the cookie dough. Firmly press the third cake on top of the cookie dough layer.

Step 12

Frost the top and sides of the cake with the chocolate buttercream, using an offset spatula to smooth out the sides of the cake. If desired, roll the remaining cookie dough into little cookie dough truffles and decorate the top of the cake. If not, you can always just save the remaining edible cookie dough for snacking on later!