Begin by cooking the elbow macaroni according to package directions until al dente, then drain and set aside.
In a medium saucepan, warm the whole milk or heavy cream over medium heat without boiling.
Melt the butter in the warm milk, then gradually add the sharp cheddar, mozzarella, and Parmesan cheeses, stirring constantly until everything melts into a smooth sauce.
Season the cheese sauce with garlic powder, mustard powder, salt, and pepper to enhance the flavors.
Mix in the sour cream if you prefer a creamier texture.
Combine the cooked macaroni with the cheese sauce, stirring until each piece is well coated.
If you like, sprinkle breadcrumbs on top and transfer to a baking dish.
Place under a preheated broiler for a few minutes until the breadcrumbs turn golden and crispy.
Garnish with freshly chopped parsley before serving to add a fresh touch.
