Texas Sheet Cake

Bahan-bahan (15 porsi)

• 1 cup unsalted butter (cut into pieces)
• 1 cup water
• ⅓ cup unsweetened cocoa powder
• 2 cups all-purpose flour
• 1 ½ cups granulated sugar
• ½ cup brown sugar
• 1 teaspoon baking soda
• ¾ teaspoon salt
• ½ teaspoon instant coffee (optional)
• ½ cup sour cream
• 2 large eggs (room temperature)
• 1 teaspoon vanilla extract
• 6 Tablespoons milk
• ½ cup butter (cut into pieces)
• 6 tablespoons unsweetened cocoa powder
• 4 cups powdered sugar (sifting is recommended (after measurinto avoid any lumps))
• ¾ teaspoon vanilla extract