Preheat oven to 450 degrees F. Lightly pound the chicken breasts to slightly flatten them.
Spray a baking dish with olive oil spray and place the chicken breasts in the dish, flat side up. Lightly spray the chicken breasts with olive oil spray, or brush with olive oil. Sprinkle with the salt, pepper, garlic powder and oregano. Bake for 10 minutes.
Remove the baking dish from the oven. Turn the chicken breasts to the other side. Top each chicken breast with 1 tablespoon of marinara sauce, ¼ cup shredded mozzarella, 2 slices of chorizo or pepperoni, 2 slices of pepper and a few olives.
Return the baking dish to the oven. Bake until chicken is cooked through and cheese is melted, about 10 more minutes. Serve immediately.