Fill a large pot with water and bring it to a boil. Add a pinch of salt. Cook the elbow macaroni according to package instructions until tender. Drain well.

Preheat your oven to 375°F (190°C). Lightly grease a baking dish with butter or cooking spray. This helps prevent the pasta from sticking while baking.

Place a saucepan over medium heat. Add butter and let it melt completely. Sprinkle the flour into the butter. Whisk constantly for about two minutes.

Slowly pour milk into the roux while whisking. Continue stirring until the sauce thickens. This step creates a smooth and creamy base for the cheese sauce.

Lower the heat and add shredded cheddar and Monterey Jack cheese. Stir gently until the cheese melts completely and the sauce becomes smooth and creamy.

Add garlic powder, paprika, salt and black pepper to the cheese sauce. Stir well so the spices mix evenly. The sauce should smell rich and flavorful.

Add the cooked macaroni to the cheese sauce. Stir gently until every piece of pasta is coated. This creates the creamy base for the casserole.

Pour the mac and cheese mixture into the prepared baking dish. Spread it evenly using a spoon so the casserole bakes evenly.

Mix breadcrumbs and Parmesan cheese in a small bowl. Sprinkle this mixture over the pasta. The topping becomes golden and crispy while baking.

Place the baking dish in the oven. Bake for about 20 minutes until the top looks golden and the cheese sauce bubbles slightly.