Preheat & prep: Preheat oven to 375°F (190°C). Lightly grease a baking dish large enough to hold the chicken in a single layer (about 9×13 inch or similar).
Pat chicken dry: Pat the chicken breasts dry with paper towels. If breasts are thick at one end, consider butterflying them or pounding gently to an even thickness (about ¾–1 inch) so they cook uniformly.
Make the creamy topping: In a medium bowl combine the mayonnaise (or Greek yogurt), grated Parmesan, seasoning salt, black pepper, garlic powder, and optional Dijon or lemon juice. Stir until smooth and well blended. Taste and adjust seasoning — Parmesan is salty, so add salt sparingly.
Coat the chicken: Place chicken breasts in the prepared dish. Spread the creamy mixture evenly over the top of each breast so they are well covered.
Bake: Bake uncovered in the preheated oven for 40–45 minutes, or until the internal temperature of the thickest part reaches 165°F (74°C) on an instant-read thermometer. The topping should be set and lightly golden. If the tops brown too quickly, tent loosely with foil for the last 5–10 minutes.
Rest & serve: Remove from the oven and let rest 5 minutes before serving to allow juices to redistribute. Garnish with chopped parsley or chives. Serve with steamed vegetables, rice, mashed potatoes, or a green salad.
Troubleshooting & consistency tips
Chicken dry? Overcooking is the most common cause. Use an instant-read thermometer and remove at 160–162°F, then tent and rest until it reaches 165°F. Even a minute or two saved in the oven makes a noticeable difference.
Topping too runny? Greek yogurt yields a firmer topping than mayonnaise. If your mixture seems loose, add an extra tablespoon of Parmesan or a teaspoon of breadcrumbs to thicken.
Topping browns too fast? Lower oven to 350°F (175°C) and increase bake time slightly, or tent with foil for the last part of baking.
Uneven cooking? Pound thicker breasts to even thickness or butterfly large breasts so all pieces finish at the same time.
