In a medium bowl, toss the ramen, egg and Parmesan together.
In a 10-inch cast-iron skillet, heat some oil over medium heat. Once hot, add the ramen mixture in an even layer and press down with a spatula. Let cook for 1 to 2 minutes. Sprinkle with half of the mozzarella, spread tomato sauce over, then the remaining cheese, top with pepperoni and sprinkle with oregano.
Place skillet into the oven and bake for 15 minutes. Slice into wedges and enjoy!