Dough: In a bowl, break up eggs and sugar to form a thick cream. To the resulting cream add the butter, flour, baking powder and vanilla. Stir until the solution is homogenized. Then add the diced apples and mix again. The full form of muffins to 2/3 and bake in a preheated oven at 180C until ready (about 30 minutes). Cream: In bowl, beat the butter, which should be at room temperature, about 1 minute. Then add powdered sugar and vanilla and whip at high level for another 4-5 minutes until a fluffy cream. With Posh or spraying Apply the cream on the already finished and gone cold muffins. Decorate with fruit of your choice.