Dark Chocolate Sheet Cake with Peanut Butter Frosting
 
Makes 1 (13x9-inch) cake
Ingredients
  • 4 ounces (115 grams) 60% cacao semisweet chocolate, chopped
  • 6 tablespoons (84 grams) unsalted butter
  • 1½ cups (360 grams) water
  • 1 cup (200 grams) granulated sugar
  • 1 cup (220 grams) firmly packed light brown sugar
  • ¼ cup (21 grams) unsweetened cocoa powder
  • ⅔ cup (160 grams) sour cream
  • 1 teaspoon (4 grams) vanilla extract
  • 2 large eggs (100 grams), lightly beaten
  • 2 cups (250 grams) all-purpose flour
  • 2 teaspoons (10 grams) baking powder
  • 2 teaspoons (10 grams) baking soda
  • 1 teaspoon (3 grams) kosher salt
  • Peanut Butter Frosting (recipe follows)
  • Garnish: chopped semisweet chocolate
Instructions
  1. Preheat oven to 350°F (180°C). Line a 13x9-inch baking pan with parchment paper, letting parchment extend over sides of pan. Spray parchment with baking spray with flour.
  2. In a large bowl, place chocolate and butter.
  3. In a medium saucepan, whisk together 1½ cups (360 grams) water and sugars; bring to a boil over medium-high heat, stirring occasionally, until sugar is dissolved. Whisk in cocoa. Pour over chocolate mixture, and let stand for 2 minutes. Stir until chocolate is melted and mixture is combined. Stir in sour cream and vanilla. Whisk in eggs.
  4. In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Slowly add flour mixture to chocolate mixture, whisking just until combined. Pour batter into prepared pan.
  5. Bake until a wooden pick inserted in center comes out clean, 30 to 35 minutes. Let cool completely in pan. Top with Peanut Butter Frosting; garnish with chocolate, if desired.
Recipe by Bake from Scratch at https://bakefromscratch.com/dark-chocolate-sheet-cake-peanut-butter-frosting/