Melt the dark chocolate with the butter in a water bath and let cool down a little. Beat the eggs with the sugar and vanilla sugar until frothy until a creamy mixture is formed. Mix the flour and cocoa powder and stir alternately with the cream into the egg and sugar mixture. Stir in the chocolate butter. Chop the milk chocolate and fold into the batter.
Grease the muffin tin and fill it with the batter. The dough is enough for 10 pieces.
Bake at 200 ° C for 15 minutes. Let cool in the tin for about 30-45 minutes.
Glaze:
Melt the chocolate together in a double boiler and then let it cool down until the chocolate starts to harden again. Now add the cream very slowly, stirring constantly, and spread the glaze over the muffins.