Preheat the oven to 400 degrees F. Using kitchen shears, snip four 1/2 inch cuts around the edges of each pepperoni slice, leaving the center uncut. Each pepperoni should look like a circular cross. (See post image for clarification.)
Press each pepperoni down into a mini muffin pan. Bake for 5-6 minutes, until the edges are crispy, but the pepperoni is still red. Let the pepperoni cool in the pans for 5 minutes to crisp, so they hold their shape. Then move the cups to a paper towel lined plate to remove excess oil.
Wipe the grease out of the muffin pan with a paper towel, then return the cups to the pan. Place a small basil leaf in the bottom of each cup, followed by 1/2 teaspoon of pizza sauce, a mini mozzarella ball, and an olive slice.
Place back in the oven for 2-3 minutes, until the cheese starts to melt. Allow the cups to cool again for 3-5 minutes before serving.