Preheat the oven to 180°C. Line a 12-hole muffin tin with brown or red patty cases
Place the flour, sugar, baking powder, bicarbonate of soda, cocoa, butter, eggs, vanilla and sour cream in a food processor. Process for 1 minute or until a thick batter forms. Divide the batter evenly between the patty cases until they are each 3/4 full.
Bake for 20 minutes or until the cupcakes have risen and a skewer inserted comes out clean. Remove from the oven and allow to cool in the tray for 5 minutes, before transferring to a cooling rack to cool completely
Icing and Decorating the Cupcakes
To make the ganache, place the chocolate and sour cream in a heatproof bowl over a pan of simmering water. Stir with a metal spoon for 3 minutes or until the chocolate melts and becomes smooth. Remove the bowl from the heat
Place a large milk chocolate button in the centre of each cupcake. Place two white chocolate buttons on top for eyes, using a little ganache to stick them on securely. Add a red Smartie for the nose, again using the ganache to help secure the Smartie. Use the black icing pen to draw eyes in the centre of the white chocolate buttons, and then insert two half pretzels in the cupcake for antlers