Boil salted water and cook elbow macaroni until al dente
Drain the pasta and set it aside
Melt butter in a saucepan over medium heat
Whisk in flour and cook for 1 to 2 minutes
Slowly whisk in milk until smooth
Cook, stirring, until the sauce thickens
Add shredded cheese and stir until melted
Season with salt, pepper, and optional mustard powder or paprika
Combine the cheese sauce with the cooked macaroni
Stir until the pasta is fully coated
Serve immediately while creamy and hot