Preheat the oven to 375º. Spray cast iron skillet lightly with nonstick spray.
Rub mushrooms with a damp paper towel to clean dirt from the mushrooms. Pat dry with a paper towel. Remove mushroom stems and set mushroom tops aside.
In a medium mixing bowl, combine bread crumbs, basil, parmesan cheese, melted 5 tbsp butter, salt & pepper. Set aside.
In a medium bowl, whisk together chicken broth and minced garlic and pour into cast iron skillet.
Using a spoon or your hands, scoop cheese & butter mix into the mushrooms. Place caps into cast iron skillet.
Bake for 10 minutes. Remove from oven. Melt remaining 3 tbsp butter and spoon over top of mushrooms.
Switch oven from bake to Broil Low. Place mushrooms back in oven and Broil for 2-3 min until breadcrumbs are golden brown but watch very closely on broil so it doesn’t burn.
Remove baking dish from the oven. Sprinkle with fresh parsley and serve with a fresh lemon wedge.
