For the chocolate mousse, peel and pit avocados. Drain compote cherries, reserving juice. Place 6 tablespoons juice and avocado pieces with cocoa powder and cinnamon in a blender and blend for about 3 minutes until homogeneous.
Put the drained compote cherries (except for 2 tbsp. for decoration) into two dessert glasses. Pour the mixture into the dessert glasses and add the remaining cherries. Be sure to chill and serve ice cold!