Preheat oven to 180ºC and line a baking tray with baking paper.
For the pizza bases, place muffin halves on the baking tray, cut side up.
Spoon 1/2 tbs pizza sauce on each muffin half and spread to the edges of muffin with the back of a spoon.
Place one slice of mozzarella in the centre of each pizza base.
Lay out all of the toppings and get the kids involved in decorating the pizzas to resemble monster faces. Use sliced olives for eyes, capsicum for noses or mouths, salami for teeth and asparagus rosemary for eyebrows. To make the spiders, halve an olive lengthways for the body and crossways for the head, with thin slices of olive (cut crossways and in half) for the legs.