Reduced-Fat Chocolate Sheet Cake | America's Test Kitchen

Ingredients

• 3 ounces (85 grams) semisweet chocolate, chopped
• 2 tablespoons chocolate syrup
• 1 1/2 cups (7½ ounces/213 grams) all-purpose flour
• 3/4 cup (2¼ ounces/64 grams) unsweetened cocoa powder
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1/4 teaspoon table salt
• 6 tablespoons unsalted butter, softened, cut into 1-inch pieces
• 1 1/4 cups (8¾ ounces/248 grams) granulated sugar
• 2 large eggs
• 1 teaspoon vanilla extract
• 2 teaspoons instant coffee granules
• 1 1/2 cups low-fat buttermilk
• 4 tablespoons unsalted butter, cut into 4 pieces
• 1 ounce (28 grams) unsweetened chocolate, chopped
• 1/4 teaspoon instant coffee granules
• 3 cups (12 ounces/340 grams) confectioners' sugar
• 1/2 cup skim milk