In a microwave safe dish (or over a double boiler), combine the chocolate chunks and raspberry liqueur. Heat on HIGH for 1 minute, stir with a rubber or silicone spatula until smooth. If there is still a great deal of unmelted chocolate, you can return the bowl to the microwave in 10 second bursts, stirring well after each burst, until the chocolate is perfectly melted and smooth. Add to the blender with the tofu and vanilla extract. Put the lid in place and blend for 1 minute or until smooth. Pour into dessert bowls or a big bowl, cover with plastic wrap and refrigerate for 1 to 2 hours, or until well chilled and set.