In a small saucepan, scald the cream over moderate heat. Add the chocolate and remove from the heat. Let stand until melted, about 3 minutes. Stir until smooth.
In a bowl, whisk the mascarpone until fluffy. Whisk in the sugar, liqueur and chocolate cream. Refrigerate for 15 minutes, until firm. Spread 4 of the waffle cookies with the chilled chocolate cream, top with the remaining 4 cookies and refrigerate. Serve with the fresh berries.