Place chicken in a large gallon sized ziplock bag with the Italian dressing and marinate for 30 minutes, or up to 3-4 hours.
When you’re ready to bake the chicken, preheat your oven to 350F.
Remove the chicken from the Italian dressing then seasoning with salt, pepper and Italian seasoning.
Place the chicken in a large casserole dish, leaving room between each piece. Top with pizza sauce.
Bake for 15 minutes, then top with mozzarella cheese, pepperoni and additional toppings of your choice. Continue baking for another 20 minutes, or until the chicken reaches an internal temperature of 165F.