Dark Chocolate Sheet Cake with Dark Chocolate Frosting

Ingredients

• 1.75 cups all-purpose flour
• 1 cup dark cocoa powder , such as Hershey's® Special Dark
• 2 teaspoons baking soda
• 0.5 teaspoons salt
• 1 cup firmly packed dark brown sugar
• 0.5 cups white sugar
• 0.5 cups unsalted butter , softened
• 2 large eggs , at room temperature
• 2 teaspoons vanilla extract
• 1 cup strong brewed coffee , at room temperature
• 1 cup buttermilk , at room temperature

Instructions

1. 1

   Gather all ingredients.

2. 2

   Preheat the oven to 350 degrees F (175 degrees C). Grease a 10x15-inch rimmed baking sheet and line the bottom of the pan with parchment paper.

3. 3

   Whisk flour, cocoa powder, baking soda, and salt together in a bowl until thoroughly combined. Set aside.

4. 4

   Beat brown sugar, white sugar, and butter together in a large bowl with an electric mixer until light and fluffy. Beat in eggs one at a time, mixing well after each addition.

5. 5

   Mix in vanilla extract.

6. 6

   Add in 1/3 of the flour mixture, and mix until just combined.

7. 7

   Add in 1/2 of the coffee and buttermilk, and mix until just combined.

8. 8

   Continue alternating additions of the flour mixture with coffee and buttermilk, mixing just until combined.

9. 9

   Pour batter into the prepared pan; smooth into an even layer. Tap pan firmly on the counter several times to remove air bubbles.

10. 10

    Bake in the preheated oven until a toothpick inserted into the center of the cake comes out with a few moist crumbs, about 25 minutes. Do not overbake. Place cake on a wire rack and allow to cool completely.

11. 11

    Meanwhile, make the frosting. Beat butter in a large bowl until completely smooth.

12. 12

    Mix in cocoa powder, espresso powder, and salt until throughly combined. Mix in vanilla.

13. 13

    Add in powdered sugar 1 cup at a time, mixing well after each addition.

14. 14

    Pour in heavy cream and beat until frosting is light and fluffy, 2 to 3 minutes. If frosting is too thick, add more heavy cream.

15. 15

    Spread frosting over the cooled cake.