Spray a large skillet with cooking spray and set to medium heat.
Cook turkey and Italian seasoning in the skillet until turkey is no longer pink, breaking up meat and mixing as it cooks. Transfer meat to a medium bowl.
Mix together spaghetti sauce and Parmesan cheese with the ground turkey.
On one half of a tortilla, place a single layer of spinach leaves. Top with 1/2 cup turkey/sauce mixture and 2 tablespoons shredded mozzarella. Fold the tortilla over in half.
Spray the skillet you used to cook the ground turkey with cooking spray and carefully transfer the quesadilla to the pan. Spray top of quesadilla with cooking spray. Cook quesadilla over medium heat for 60-90 seconds on each side, or until crispy and slightly browned. Repeat steps 4 and 5 with remaining ingredients.
Optional step: Transfer cooked quesadilla to a cutting board. Using a pizza cutter, cut quesadillas into 3-4 triangles to make it easier to pick up and eat.