Begin by boiling a large pot of salted water.

Cook the elbow macaroni according to package instructions until al dente.

In a saucepan, melt the butter over medium heat.

Add the flour to the melted butter, whisking continuously for about 1 minute.

Gradually whisk in the milk, eliminating any lumps until smooth.

Stir in the garlic powder, onion powder, salt, and black pepper.

Once the sauce thickens, add the shredded cheddar and mozzarella cheese, stirring until melted and smooth.

In a large bowl, mix the cooked pasta with the cheese sauce until every noodle is coated.

Transfer the mixture to a greased 9x13-inch baking dish and sprinkle breadcrumbs on top if desired.

Bake in a preheated oven at 350°F (175°C) for 30 minutes or until bubbly and golden.

For an extra crispy top, broil for the last 2-3 minutes.