Preheat oven to 355°F (180°C)
Combine lard and butter at room temperature, and add sugar. Beat with electric mixer for at least 10 min. Add the egg and beat for another minute. Mix in vanilla extract, milk and rum. Combine flour and cocoa powder and add to the mixture. Beat well.
Pipe dough into round circles onto the greased baking sheet using an extra large star attachment.
Bake for 8 – 10 minutes, cool on baking sheets for 2 minutes; remove to wire racks to cool completely.
Decorate with chocolate topping and nuts. Serve cold.