In a large skillet over medium heat, cook the sausage, breaking it up as you go.  Cook until no longer pink and cooked through.  Remove the sausage to a paper towel lined plate to drain.  

In the same skillet, saute the onions and peppers until soft and translucent, about 5 minutes.  Remove to a bowl and wipe out the skillet.

Lay out the tortillas and spread about 2 tbsp of pizza sauce on each.  On three of the tortillas (leave three to go on top) Sprinkle about ⅓ of a cup of the shredded mozzarella cheese onto each tortilla.  Layer with the sausage, onion & pepper mixture, and pepperoni and top with ⅓ additional cup of mozzarella.  Place the remaining three tortillas sauce side down on top.

Return the skillet to medium heat and spray with olive oil spray.  Place one quesadilla in the pan and cook for about 3-5 minutes per side until browned and crisp and the cheese is melted.  Repeat the process with the remaining two quesadillas.  

Slice into quarters and serve!