For the chocolate-maroni mousse, first chop the dark and milk chocolate into small pieces and melt over a water bath.
Beat the egg yolks with the powdered sugar until foamy, add the melted chocolate and the Baileys and stir in. Beat the GUMA Pâtisserie Cream with the mixer for about 4 minutes until stiff and fold in carefully. Pour the mousse into the glasses (only 2/3 full) and chill for at least 4 hours.
Blend the chestnut puree with the powdered sugar and Baileys until smooth and refrigerate until further processing.
To finish, beat the GUMA Pâtisserie Creme with the powdered sugar for about 4 minutes until firm but still fluffy, pour into a piping bag fitted with a star nozzle and pipe onto the chocolate mousse. Press the chestnut puree with a (well-cleaned) garlic press over the dressed cream.
Serve the chocolate and chestnut mousse.