Preheat oven to 425F. Wash potatoes well and pat dry. Poke holes with a fork several times around the potatoes. Rub with olive oil and season with salt and pepper. Bake for about 45-50 minutes or until soft on the inside.
Slit open the potatoes and use a fork to fluff the insides. Mix in some marinara sauce and pepperoni slices. Sprinkle cheese on top and add a few more pepperoni slices if desired.