For the cupcakes, beat the soft (room temperature) butter in a bowl with the sugar until pale and fluffy. Then add the egg and stir in well. Add the sifted flour, the pinch of salt and the baking soda. Mix everything together with a cooking spoon. Then add milk, vanilla and heavy cream and blend until the batter is just combined.
Pour the cupcake batter into the mini cupcake pan and bake for 10 - 12 minutes. Remove from oven and let cool.
Prepare your ingredients and tools for the ghost sheets. Make your butter cream frosting or take out of the fridge.
Pipe the buttercream frosting in a single layer on top of the cupcakes. Stack up two Mini-Marshmallows using frosting as glue and add it to the cupcake. Allow the frosting to dry as you make your ghosts.
Massage the fondant with your hands coated in Crisco. Roll out and cut 3 inch circles. Carefully add the circles over the marshmallows and position the fondant to make the folds.
Prepare the food coloring. Using a toothpick, add bloody details and faces. Smiling or grim, whatever you prefer. Create somd red marks at the sheet edges.