Heat olive oil in a large skillet on medium heat. Add in bell peppers, spinach, mushrooms, and onions. Cook for about 5 minutes, or until veggies become tender. Season with Italian seasoning, garlic powder, and salt and pepper to taste. Remove from heat.

Spread a thin layer of pizza sauce over each tortilla.

On one half of the tortilla, add about ¼ cup of mozzarella cheese, a serving of the cooked veggies, and pepperoni. Fold the tortilla in half, bringing the half without toppings up and folding it over the top.

Spray a large skillet with non-stick cooking spray. Cook the quesadilla for about 2-3 minutes on each side, flipping once, until toasted on the outside and the cheese is melted.

Remove from heat, cut into wedges, and serve. Dip in extra marinara sauce or ranch, if desired.