01 -
Preheat the oven to 375°F (190°C) and position the rack in the upper third for optimal browning.
02 -
Bring a large pot of salted water to a boil and cook penne pasta for 2 minutes less than package instructions. Drain well.
03 -
Return drained pasta to the pot, add marinara sauce and one-third of the pepperoni slices, then stir until evenly coated.
04 -
Transfer the pasta mixture to a 9x13 inch (23x33 cm) baking dish, spreading evenly. Sprinkle shredded mozzarella over the top and arrange remaining pepperoni slices on the cheese.
05 -
Bake uncovered for 20 minutes until cheese is melted and bubbly. Then broil for 2-3 minutes to crisp pepperoni and cheese, watching closely to avoid burning.