Cook 1 pound of rotini pasta in a large pot of boiling salted water until al dente, following the package instructions. Drain and set aside.
In a large saucepan, melt 4 tablespoons of butter over medium heat. Add 1/4 cup of all-purpose flour, whisking continuously until a smooth paste forms.
Gradually pour in 2 cups of half & half, whisking constantly to avoid lumps. Cook for about 3-4 minutes until the mixture thickens slightly.
Lower the heat and add 12 ounces of deli-sliced American cheese, tearing the slices for easier melting. Stir until melted and smooth.
Mix in 1 cup of shredded cheddar cheese and 1/2 cup of grated Parmesan cheese, stirring until fully melted into the sauce.
Add 1 teaspoon of paprika, 1 teaspoon of salt, 1/2 teaspoon of black pepper, 1/2 teaspoon of garlic powder, and 1/2 teaspoon of mustard powder. Stir until well combined.
Add the cooked rotini pasta to the cheese sauce, gently stirring to coat the pasta thoroughly.
Transfer the mac & cheese to a serving dish, serve hot and enjoy!
Notes
While rotini is suggested, you can substitute it with other pasta shapes like penne or fusilli, which also hold the sauce well.Store leftover mac & cheese in an airtight container in the refrigerator for up to 3 days. Reheat gently over low heat, adding a splash of milk to restore creaminess.For longer storage, freeze portions in a freezer-safe container for up to 2 months. Thaw in the refrigerator overnight before reheating.