Boil macaroni in salted water until al dente. Drain and set aside.
Melt butter in a saucepan over medium heat. Whisk in flour and cook for 1-2 minutes until golden.
Gradually whisk in milk and cream. Stir in Dijon mustard, garlic powder, paprika, salt, and pepper.
Add cheddar, Gruyère, and Parmesan cheese, stirring until melted and creamy.
Preheat oven to 375°F (190°C). Mix macaroni with cheese sauce and transfer to a greased 9×13-inch baking dish.
Toss breadcrumbs with melted butter, sprinkle on top, and bake uncovered for 20-25 minutes until golden.
Let cool slightly, garnish with parsley, and serve warm.