In a small bowl, combine the mayonnaise, 3/4 cup Parmesan, seasoning salt, black pepper, and garlic powder. Set aside.
Place diced chicken into a greased 9x13 baking pan.
Spread mayonnaise mixture evenly on top of the chicken.
Sprinkle remaining Parmesan cheese on top of mayonnaise mixture.
Place baking pan in preheated oven, 375 degrees, and bake for 30-35 minutes.
Remove from oven and serve over pasta, rice, or by itself.