In a bowl sifted flour, add baking powder and salt and mix. Grate the peel of two oranges, then squeezed juice them. Orange peel and 1 cup sugar is added to the bowl with the flour. In another bowl mix the milk, melted butter, juice and egg. Stir well and add vanilla. Gradually in the wet mixture add the flour. Pour the mixture into an oiled form. Bake 20-25 minutes in preheated oven. During this time, mix sour cream and 1/2 cup sugar mix. Once cool, the cake is coated with glaze and sprinkle with grated chocolate.