In a small dish, stir together the salt, pepper, paprika, garlic powder, fennel seed and red pepper flakes to make a sausage seasoning. Place the ground turkey in a mixing bowl and pour the seasoning mix over the top. Use a spoon or your hands to thoroughly mix the seasoning into the ground turkey. If possible, refrigerate for a couple hours before using to really maximize the flavor.

Preheat the oven to 400 degrees. Line a large baking sheet with aluminum foil and lightly mist with cooking spray. Set aside.

Bring the olive oil over medium heat in a large skillet. Add the seasoned ground turkey, onions and garlic and cook, breaking the meat up into bite-sized pieces, until the onions are softened and the meat is cooked through. Add the cream cheese and parmesan cheese and stir together. Continue cooking over medium heat until the cheeses are melted. Stir in the bread crumbs, basil and parsley.

Place the melted butter in a small dish. Arrange the mushroom caps (missing) stem side up on the prepared baking sheet. Using a pastry brush, brush the mushrooms caps with butter. Spoon the turkey sausage mixture evenly into the mushroom caps. Place in the oven and bake for 12-15 minutes.