Beat eggs with sugar. Add the oil and sour cream and crashed. Add vanilla and gradually the flour mixed with baking powder. The mixture was placed in a greased form, leaving about 1/2 cup thereof. Add cocoa and stir well. Colored mixture is poured in the form on the white dough into a circle shape and place in preheated oven. When I bake a 160C degrees lower and fan of BBQ second from the bottom in 35 minutes. Check with wooden skewers that is baked and when ready immediately removing from the oven. Leave 10 minutes and then remove it from the form. When completely cool Spray glaze optional, or sprinkle with powdered sugar. * The shape is 22 cm.