Cook the macaroni according to package directions. Drain and set aside.

In a large saucepan, melt butter over medium heat. Stir in flour and cook for 1-2 minutes, until it forms a roux.

Slowly whisk in milk, stirring constantly to prevent lumps. Cook for 3-4 minutes, until the mixture thickens.

Reduce heat and stir in pepper jack cheese, cheddar cheese, garlic powder, onion powder, salt, and pepper. Stir until cheese is melted and the sauce is smooth.

Add cooked macaroni to the sauce, stirring to coat.

If desired, sprinkle with fresh cilantro before serving.