In a large mixing bowl, combine softened butter and cream cheese. Add eggs and stir with a whisk until mixture is smooth.
Stir in corn, cream-style corn, onion, salt, and pepper. Add corn muffin mix and stir until well combined.
Spray an 11x7-inch baking dish with non-stick cooking spray. Pour batter into prepared dish.
Bake at 375℉ for 45-50 minutes until a wooden pick inserted in the center comes out clean.
