For one cake baked in a 32x22x10cm (13x9x2 inch) pan
1. Mix together in a bowl 2 tablespoons of soft butter, 100 grams of 30% fat cream cheese (Napoleon) and a few drops of vanilla.
2. When it is smooth, slowly start adding powdered sugar and mix until you get a good spreading consistency (the mixture should not fall off the spoon or should not run off the beaters). This will be about 300 grams of powdered sugar.
3. Spread onto a cooled cake. (If the cake is not completely cool, the frosting will melt)
For a 20 cm (8 inch) round double layer cake, double the recipe so that you will have enough to spread in the middle and up the sides.