Cook linguine pasta according to package instructions, until al dente. Heat oven to 350 degrees F. Lightly coat a 9x13" casserole dish with non stick spray and set aside.
Meanwhile, in a large bowl, combine melted butter, cream of mushroom soup, sour cream, chicken broth, salt, garlic powder, and black pepper. Whisk until smooth and combined.
Add in the freshly chopped parsley, cooked chicken and drained, cooked pasta. Stir until combined. Pour creamy pasta mixture into prepared casserole dish.
Sprinkle mozzarella cheese and parmesan cheese over the top. Cover with foil and bake for 30 minutes. Remove foil and continue baking for an additional 10 minutes, until bubbly in center. Enjoy!
*you can swap out the cream of mushroom soup with cream of chicken soup if desired. Recipe is great for making ahead - freeze before baking for up to 3 months. Defrost completely in fridge before baking according to recipe instructions.