Preheat the oven to 400°F and prepare a 9x13-inch baking dish with nonstick spray, set aside.
Use a sharp knife to butterfly the chicken breasts.
4 boneless skinless chicken breasts
Stuff each chicken breast with a bit of the cheese and a few pepperoni slices, then close to keep in place.
6 ounces pepperoni slices, 3 cups shredded mozzarella cheese
Brush olive oil on the top of each chicken breast and season with salt, pepper and Italian seasoning.
3 Tablespoons extra virgin olive oil, ½ teaspoon salt, ¼ teaspoon ground black pepper, ½ teaspoon Italian seasoning
Place the chicken in the prepared baking pan and surround with the petite diced tomatoes.
1 (14 oz) can petite diced tomatoes
Carefully spoon the pizza sauce over the chicken breasts, and tomatoes.
2 (14 oz) jar pizza sauce
Top the chicken breasts with mozzarella cheese, pepperoni slices and fresh basil.
3 cups shredded mozzarella cheese, 6 ounces pepperoni slices, 2 Tablespoons fresh basil
Bake in a preheated oven for about 45 minutes or until the internal temperature of chicken reads 165°F.
Remove from the oven and allow to cool slightly before serving.