In a large saucepan, boil penne noodles according to the directions on the package. Salt the boiling water with a pinch of salt.
Spray a 9x13-inch baking dish with nonstick cooking spray for easy cleanup.
Drain noodles and add to the prepared dish.
Pour spaghetti sauce over noodles and stir until noodles are covered in sauce.
Dice pepperoni and add to noodles. Reserve a few pepperoni as a topping.
Top noodles completely with the mozzarella cheese slices.
Sprinkle reserved pepperoni to the top of the cheese.
Bake in a 350 degree F oven for 20 minutes or until cheese is melted and the edges are golden brown.
Serve with side salad and parmesan cheese crisps.
Notes
Note 1 - Use a homemade sauce or purchase a low FODMAP version from the grocery store. Both Prego and Rao's have sensitive spaghetti sauce options. Note 2 - To keep it low FODMAP, use a pepperoni without garlic or onion listed in the ingredients. Look at the deli counter pepperoni options. Low FODMAP Notes: Selected ingredients are based on current serving sizes measured by the Monash University FODMAP App at the time of publishing. As always, follow your gut and modify as needed.