In a large mixing bowl, combine the cooked macaroni, cheddar cheese, mozzarella cheese, crumbled bacon, and ranch dressing.
Place a generous scoop of the mixture onto one-half of a tortilla and fold over the other half.
In a large skillet, melt a tablespoon of butter or heat a splash of oil over medium heat.
Place the filled tortilla into the skillet and cook for about 3-4 minutes or until the bottom is golden brown.
Flip the quesadilla carefully and cook for another 3-4 minutes until both sides are crispy and golden.
Once cooked, cut into wedges and serve warm.
