Mint Chocolate Chip Cake


2 1/4 cups cake flour, plus more for dusting pans
1 cup whole milk, at room temperature
6 large egg whites, at room temperature
2 tsp vanilla extract
1 1/2 tsp mint extract
5 drops green food coloring
1 3/4 cups sugar
4 tsp baking powder
1 tsp table salt
12 T unsalted butter, softened but still cool
1 cup mini chocolate chips

How to make it : 

1. Adjust oven rack to middle position and heat oven to 350 degrees. Spray three 8-inch round cake pans with nonstick cooking spray, dust with flour, and tap pans to remove excess flour. Mix milk, egg whites,  vanilla, mint and food coloring together in 2-cup measuring cup.  (If you forgot to bring them to room temperature, place measuring cup in a sink of warm water until mixture is cool, not cold, about 65 degrees.)

2. Mix flour, sugar, baking powder, and salt together in bowl of electric mixer at low speed. Add butter and beat at low speed until mixture resembles moist crumbs, with no powdery streaks remaining. 

3. Add all but 1/2 cup of milk mixture to crumbs and beat at medium speed (or high speed if using handheld mixer) for 1 1/2 minutes. Add remaining 1/2 cup of milk mixture and beat 30 seconds more. Stop mixer and scrape sides of bowl. Return mixer to medium (or high) speed and beat 20 seconds longer.  Stir in 1 cup mini chocolate chips.

4. Divide batter evenly between three prepared cake pans and using rubber spatula, spread into even layer. Arrange pans at least 3 inches from the oven walls and 3 inches apart. (If oven is small, place pans on upper middle and lower middle racks in staggered fashion to allow for air circulation.) Bake until thin skewer or toothpick inserted in the center comes out clean, 21 to 25 minutes. 

5. Rest cakes in pans 10 minutes, then loosen from sides of pans with a knife. Invert onto large plate, reinvert onto wire racks. Cool completely, about 1 1/2 hours.

Luscious Chocolate Buttercream Frosting
20 T (2 1/2 sticks) unsalted butter, cut into 20 pieces and softened
8 oz. bittersweet chocolate, melted and cooled
1 tsp vanilla extract
1/8 tsp salt
2 cups confectioners' sugar
1 1/2 cups mini chocolate chips

1.  With electric mixer fitted with whisk attachment, beat butter, melted chocolate, vanilla, and salt on medium-high speed until combined.  Reduce speed to medium-low.  With machine running slowly, add confectioners' sugar and mix until smooth, about 1 minute.  Increase speed to medium-high and beat until light and fluffy, 3 to 5 minutes.

2.  To assemble:  Place 1 cake round on serving platter.  Spread 3/4 cup frosting over cake, then top with second cake round.  Spread another 3/4 cup frosting over cake, then top with third cake round.  Spread remaining frosting evenly over top and sides of cake.  Press mini chocolate chips onto sides of cake.  Serve.