PREPARATION
Beat in the mixer butter together with the natural sweetener isostevia for a few minutes, until they get soft and then pour the eggs one by one. Add yoghurt and vanilla extract. Pour flour and the pastry color. In a bowl stir baking soda together with cocoa powder and vinegar and pour the mixture into the mixing bowl. Mix it in low speed about 1-2 minutes, so that the ingredients will bind together.
Cover the inner sides of the 2 baking forms with non-stick baking paper and pour the mixture. Bake in a preheated oven for 40 minutes at 180?C. Take it off the oven and let it cool. As it is cool, separate each cake in two horizontally slices.
Leave the cream cheese in room temperature and beat it for a few minutes together with isostevia, vanilla extract and pastry cream, until you have a smooth and shiny mixture. Pour some of the mixture in the one slice of cake, cover it with the other slice and pour the rest of the mixture on the top of the cake as well as on the sides. Preserve the cake in the fridge.