Separate yolks from egg whites. Beat the egg yolks with 80 g of sugar until white. Add flour, starch, vanilla, baking powder and stepcheto. Beat the egg whites with a pinch of salt on hard snow. Combine the two mixtures as you continue stirring with a spoon. Cover rectangular baking dish (I use this oven) with greased baking paper and pour the mixture. Distribute well the edges and bake in preheated oven at 180C for 12-15 minutes. Beat the soft butter with powdered sugar, milk, vanilla essence and rum (better with cherry liqueur, but this is optional - I I used rum). Finally, add the cocoa. Clean cherries stoned them. Once you have baked the base, pull it out on a towel, take the paper from him and let cool completely. Set aside 1/3 of the cream to cover the cake with the remaining cream smear the base, cut in small pieces cherries on top without cover everywhere. Cut four long strips the base, making sure to have almost the same width. Wrap one strip of roll and place it in the center of the tray - upright. With other bands that go around the roll until a cake. Apply with nice rooms and a little cream on top side and leave in the fridge for about an hour. Melt the chocolate in a water bath with the butter. Half pour cake and return to the refrigerator, and the rest of chocolate keep warm. After 15 minutes, pour over cake on all sides and return to the fridge for another hour. Decorate optional.