Bring a large pot of salted water to a boil.

Add the macaroni and cook until al dente, according to package instructions.

Once cooked, drain the pasta in a colander and set aside.

In the same pot, melt the butter over medium heat.

Stir in the flour and cook for about 2 minutes to create a roux.

Gradually whisk in the milk, ensuring there are no lumps.

Once the mixture begins to thicken, remove from heat.

Stir in the cheddar and mozzarella cheese until melted and creamy.

Add garlic powder, salt, and pepper to taste.

Fold the cooked macaroni into the cheese sauce until well coated.

Transfer the mixture to an oven-safe baking dish and sprinkle breadcrumbs on top, if desired.

Bake at 350°F for about 15 minutes until golden and bubbly.