Soak gelatine in cold water. Separate eggs. Beat egg yolks, 2 tablespoons of sugar and vanillin sugar until creamy. Stir in advocaat. Dissolve the gelatine and stir into the advocaat liqueur cream.
Beat 1 cup of cream and egg white separately until stiff. Loosely fold into the cream, fill into a bowl and refrigerate for about 1/2 hour. Stir the coffee into the remaining cream, beat until stiff and stir in the remaining sugar.
Pour into a piping bag with a star-shaped spout and decorate the advocaat cream with mocha cream tuffs. Halve the chocolate truffles and decorate each tuff with 1/2 truffle.