Cake: cocoa, milk and sugar are boiled to thicken and leave to cool. The butter and powdered sugar is broken down to graying. Sift the flour with the baking powder. To the mixture with the butter add an egg, some yogurt, a little of the boiled cocoa, a little of the flour and the procedure is repeated until all products are mixed. To the mixture is added vanilla and stir well, then pour into greased with butter and sprinkled with flour cake form. Bake in a moderate oven until ready. Once the cake cool, carefully removed from the mold. frosting: The sugar is caramelized, add the butter and stir. The cake is watered with the resulting glaze. Optional sprinkle with powdered sugar.