Preheat oven to 350°F (175°C).
Cook macaroni in a pot until firm.
Drain pasta and set aside.
Melt butter in a saucepan over medium heat.
Add flour and whisk for 1 minute.
Slowly add milk, whisking until smooth.
Stir in cheddar, Gruyère, and Parmesan cheeses.
Add garlic powder, onion powder, salt, and pepper.
Cook until sauce is smooth and thick.
Mix pasta with sauce in a baking dish.
Top with breadcrumbs and parsley.
Bake for 25 minutes until golden brown.