Add one and a half cups sugar, cocoa, coffee, vanilla sugar, water, and chocolate to a saucepan. Bring to a boil, then remove from heat.

Add margarine to the pan and stir until melted.

Transfer chocolate mixture to a large bowl, then stir in flour and baking powder.

Beat egg whites until stiff peaks form, gradually adding remaining one and a half cups of sugar. Fold in yolks. Combine with chocolate mixture.

Pour into greased or lined 10×16-inch baking pan. Bake at 350 degrees Fahrenheit for 35-45 minutes. When completely cooled, ice with your favorite chocolate frosting.