White chocolate mousse
Mix the icing sugar and the mascarpone cheese.
Mix gently the whip cream and the mascarpone mixture.
Milk chocolate mousse
Melt the chocolate in a casserole. Let it cool down 15 minutes and mix it very gently with the whip cram mixture. Place in the fridge for 30 minutes.
Mix the whip cream to a hard foam.
Melt the chocolate on low heat in a casserole. Take away the casserole from the stow and let the chocolate rest for 10 minutes.
Whip the egg yellows and add in the melted chocolate and mix well.
Add the melted chocolate in the whip cream and mix gently. Place in the fridge for 30 minutes.
Preheat the oven at 250 degrees Celsius.
Pour all the ingredients in a bowl and mix well.
Place a baking paper on a baking sheet. Pour evenly the batter on the paper and place in the middle of the oven for 5 minutes. Let the cake cool down.
Spread evenly the white mousse on the cake and roll together.
Divide the cake in a small and a big part, this way you will have the log and a branch.
Cover the rolls in plastic film and place in the fridge for 1 hour.
Take out the cake and take away the plastic film and place the cake together as a bûche.
Spread evenly the milk chocolate on the cake.
Decorate the cake as you like and place cold until it is time to serve.