Preheat your oven to 400°F (200°C).
Season both sides of the chicken breasts with salt, pepper, garlic powder, and paprika.
Heat olive oil in a large oven-safe skillet over medium heat. Sear the chicken for 3-4 minutes per side until golden brown.
In a small bowl, mix Parmesan cheese, mozzarella cheese, mayonnaise, and Dijon mustard until well combined.
Spread the cheese mixture evenly over the top of each chicken breast.
Transfer the skillet to the preheated oven and bake for 15-18 minutes, or until the chicken is cooked through (internal temperature 165°F) and cheese is bubbly and golden.
Garnish with chopped parsley and serve hot.