Preheat the oven to 350 In a small bowl add the water to the german chocolate bakers chocolate. Add cocoa stir to combine then turn off heat. Easy Moist Chocolate Sheet Cake Video Recipe Chocolate Sheet Cake Chocolate Sheet Cake Recipe Bakers Chocolate Cake Recipe A 30cm x 20cm 12 x 8 inch one would also do. Chocolate sheet cake . In a mixing bowl beat egg whites until stiff peaks form set these to the side. Sift the flour baking soda baking powder salt sugar and cocoa powder. Beat with a electric whisk or wooden spoon for 2 mins until smooth. Step 2 In a large bowl sift together the flour sugar and baking soda. Preheat the oven to 350F and line a 912 cake pan with parchment paper. Lightly spray a 9x13 inch baking pan with cooking spray and set aside. How to make Chocolate Sheet Cake. Grease and flour an 11x17 inch sheet cake pan. When ready to serve let thaw at room temperature for 2 to 3 hours. How to make Texas Sheet Cake To begin add butter water and ...