Preheat your oven to 350°F (175°C).
Cook the elbow macaroni according to the package directions until al dente, then drain.
In a saucepan, melt the butter over medium heat, then add the flour to create a roux.
Gradually whisk in the milk, continuing to stir until the mixture is smooth and thickened.
Stir in the shredded cheese, salt, pepper, and garlic powder until fully melted and combined.
Combine the cooked macaroni and cheese sauce in a large bowl, mixing until the pasta is well coated.
Transfer the mac and cheese to a greased baking dish and top with breadcrumbs.
Bake for 25-30 minutes, or until the top is golden brown and crispy.
Remove from the oven and let it cool for a few moments before serving.