Prep the oven and pan: Preheat your oven to 400°F (200°C).
Lightly spray a 9x13-inch baking dish with olive oil.
Make the topping: In a bowl, mix the Greek yogurt, light mayo, Parmesan, garlic powder, onion powder, paprika, salt, pepper, and red pepper flakes if using. Stir until smooth and creamy.
Prep the chicken: Pat the chicken breasts dry with paper towels. If one end is much thicker, pound gently to even thickness (about 3/4 to 1 inch) so they cook evenly.
Season lightly: Sprinkle both sides of the chicken with a pinch of salt and pepper.
Coat the chicken: Arrange the breasts in the baking dish.
Spread the yogurt-Parmesan mixture evenly over the tops, covering from edge to edge.
Bake: Bake for 22–28 minutes, depending on thickness, until the chicken reaches an internal temperature of 165°F (74°C). The topping should look set and lightly golden at the edges.
Optional broil: For more color, broil for 1–2 minutes, watching closely.
Rest and serve: Let the chicken rest for 5 minutes. Garnish with parsley or chives and a squeeze of lemon if you like.