In the bowl of a stand mixer, combine the warm water and yeast. Stir until dissolved. Let sit for 5 minutes, until foamy. Add olive oil, salt and 2 cups of flour. Mix with dough hook. Add up to 1/2 cup flour until dough forms a ball and leaves sides of bowl. Knead at medium speed for 5 minutes.
Spray a large bowl with nonstick spray. Add dough, flip to ensure it's covered in nonstick spray. Cover with a towel and let rise, about 1 1/2 hours.
Once dough is risen, preheat oven to 475 degrees F. Add 1 1/2 tablespoons olive oil to two 10-inch cast iron skillets. Spread to cover the bottom and sides of the skillets. Divide dough in half and place a half into each prepared skillet. Gently press down until the dough reaches the edges. Cover with a towel and let rise 20 minues. It will rise slightly.
Spread half the sauce onto each pizza crust. Top each with half the cheeses and then top with pepperoni. Bake for 12 to 15 minutes, until cheese and the bottom of the crust are golden.