To prepare the chicken, mix all the required ingredients and pour the mixture over the meat. Let it marinate for at least two hours in the fridge. Grill the chicken for about 12-15 minutes until it's fully cooked.
Meanwhile, you can prepare either the ranch spread or the Parmesan crumb topping. For the ranch spread, mix grated Parmesan cheese and ranch dressing in a bowl, and set it aside. For the Parmesan crumb topping, mix butter, garlic salt, shredded Parmesan cheese, and breadcrumbs in another bowl. Make sure the crumbs are evenly moistened.
To assemble the dish, place the oven rack in the middle and preheat the broiler. Transfer the grilled chicken to an oven-safe casserole dish. Spread two tablespoons of ranch spread over each chicken breast, and then add the Parmesan crumb topping and provolone cheese on top. Broil the chicken until the cheese melts and the crumb topping turns light brown. Serve immediately.