Preheat the oven to 180°C (350°F/Gas Mark 4).
Cut each muffin in half to make 4 rounds pizza bases. Spread a thin layer of tomato puree over the cut sides of the muffins and place on a baking tray.
Using a round cutter around the same size as the muffin, cut 4 circles from the mozzarella cheese slices. (Don't worry if you can't get a full circle from the cheese as we'll cut out one end for the head).
Using a slightly smaller circle cutter, cut a semi circle off each cheese circle for the head. Using a sharp knife, cut a tall, thin triangle slice from the circles to divide them into two ‘wings’.
Carefully place your wing shaped cheese slices on the tomato covered muffin halves.
Using a small sharp knife, cut the olives into slices. You should end up with little rings. Place 2 on each head section of your pizza bugs for the eyes.
Using a mini bento cutter, cut tiny heart shapes from the pepperoni. Scatter them over the cheese for the bug's ‘spots’.
Bake in the oven for 5-10 minutes until the cheese is melted and starting to bubble.
Leave to cool for a few minutes before serving, or cool completely and pack in a lunch box.