Preheat the oven to 180C, Gas 4. Line a muffin pan with paper cases
Cream the butter and sugar until light and fluffy, add the egg and beat on high speed, until well incorporated
In a separate bowl mix together the cocoa powder, vanilla extract and red food colouring to make a thick paste; add to the batter and mix well until completely combined; add half the buttermilk, half the flour and mix until well combined; repeat with the remaining milk and flour and beat until smooth; add the salt, baking soda and vinegar and continue beating for a few more minutes
Divide the batter evenly between the muffin liner and bake for about 20 minutes or until a skewer inserted in the centre of the largest muffin comes out clean
Cool for 10 minutes in the pan, then remove from the pan and cool completely on a rack before decorating
To make the frosting – whip the butter and cream cheese for about 5 minutes, slowly add the icing sugar beating all the time; add the vanilla and mix to combine; whip for a few minutes until the frosting is light and fluffy
To decorate – spread some frosting on the top of one cupcake; roll out the white sugar paste large to cover the muffin completely and let it hang loosely around it; roll three pieces of the black sugar paste into teardrop shapes and flatten slightly use two for the eyes and one for the mouth of the ghost; to make the spider’s web, spread some frosting on another muffin, roll out some white sugar paste, cut a circle large enough to cover the top of the muffin and place on top; pipe circles with the melted chocolate on top of the sugar paste and with a toothpick, drag along the surface, from the centre to the edge of the muffin to make the web
Serving Size Makes 12 small or 8 large