Cook your macaroni according to package directions.
In a medium saucepan, melt your butter over medium heat.
Once it has melted, add in the all purpose flour. Whisk until a roux forms.
Slowly add in your milk, salt, pepper, and garlic powder and bring to a simmer.
Slowly fold in the cheese and stir occasionally until it melts and a cheese sauce is formed.
Add the cooked macaroni to the cheese sauce and stir until well combined.
Serve and enjoy!