01 - Preheat oven to 350°F. Grease a 2-quart baking dish.
02 - Boil macaroni in salted water until just al dente. Drain and set aside.
03 - Melt butter in a saucepan over medium heat, whisk in flour and cook 1 to 2 minutes until bubbling without browning.
04 - Gradually whisk in milk, stirring continuously until smooth. Cook 4 to 5 minutes until thickened.
05 - Remove from heat and stir in Dijon mustard, garlic powder, onion powder, salt, and black pepper.
06 - Incorporate grated cheddar and optional mozzarella, stirring until fully melted and smooth.
07 - Mix cooked macaroni with cheese sauce thoroughly and transfer to prepared baking dish.
08 - Combine breadcrumbs with melted butter and Parmesan cheese; sprinkle evenly over pasta mixture.
09 - Bake for 25 to 30 minutes until the topping is golden and bubbling.
10 - Allow to rest for 10 minutes before serving.