Preheat oven to 350°F (175°C).
Cook macaroni until al dente. Drain well.
In saucepan, melt butter over medium heat.
Whisk in flour until smooth and thick.
Gradually add milk and cream, whisking constantly.
Cook until sauce slightly thickens.
Stir in cheddar, mozzarella, and Parmesan.
Season with salt, pepper, and garlic powder.
Combine sauce with macaroni in a large bowl.
Pour mixture into greased baking dish.
Mix breadcrumbs with melted butter.
Sprinkle mixture evenly over top.
Bake 25–30 minutes until golden and bubbly.
Cool slightly before serving. Enjoy warm!