Bring a large pot of salted water to a boil. Add the elbow macaroni and cook according to package instructions until al dente. Drain and set aside.

In a saucepan, melt the butter over medium heat. Stir in the flour and cook for 1-2 minutes until lightly golden.

Gradually whisk in the milk, stirring constantly until the mixture thickens.

Remove from heat and stir in the cheddar and mozzarella cheeses until melted and smooth. Season with salt, pepper, garlic powder, and onion powder.

In a large bowl, combine the cooked macaroni with the cheese sauce. Mix well.

Transfer the mac and cheese to a baking dish. Top with your choice of toppings.

Bake in a preheated oven at 350°F (175°C) for 15-20 minutes until bubbly and golden.

Serve hot and let guests customize their bowls with additional toppings.