Cook pasta according to package instructions. Drain and set aside.
In a large pot, combine the smoked sausage, cheddar cheese, milk, cream of mushroom soup, frozen peas, garlic powder, and onion powder. Cook over medium heat until heated through.
Add the cooked pasta to the pot and stir to combine. Season with salt and pepper to taste.
Transfer the mixture to a baking dish. Bake in the preheated oven for 25-30 minutes, or until bubbly and golden on top.
Let cool for a few minutes before serving. Enjoy!
Notes:
This casserole can be made ahead and refrigerated. Just bake it when you're ready to eat.