Start this recipe by making the truffle filling. In a saucepan, bring the cream just to simmer over low heat. Pour the cream over the chocolate in a bowl and let stand for about 10 minutes to melt the chocolate. Add the vanilla and stir until smooth. Set aside to cool for 1 hour. When ready, place the chocolate into a mixing bowl and beat at medium speed until the mixture thickens. Meanwhile, make the biscuit base. Use a fork to mix together the chocolate wafer crumbs and butter. Grease a 6-muffin baking tin and line the cups with strips of baking sheet, cut so that they are as wide as the diameter of each cup and long enough to hang over the sides. Use the bottom of a small glass to press the crumbs over the bottom and sides of the muffin cups, building the sides up to only about 1 ½ inches. Place a raspberry in the centre of each crust and with a pastry bag fill the truffle mixture. Smooth the tops and refrigerate until set, about 2 hours.