- Bring a large pot of salted water to boil and cook pasta according to package directions until just al dente. Drain and set aside. 
- In a medium saucepan, melt the butter over medium heat. Whisk in gluten free flour until smooth. 
- Slowly pour in the milk, whisking constantly until the mixture thickens and bubbles. 
- Stir in cheddar and mozzarella cheese until melted and creamy. 
- Add garlic powder, onion powder, salt, and pepper. Taste and adjust seasoning. 
- Toss the cooked pasta into the sauce until every piece is coated. 
- If desired, transfer to a baking dish, sprinkle with gluten free breadcrumbs, and broil for 2–3 minutes until golden on top. 
- Serve warm and enjoy every cheesy bite.