Boil the Pasta: Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until al dente, about 7–8 minutes. Drain and set aside to cool slightly.

Create the Roux: In a medium saucepan, melt the unsalted butter over medium heat. Add the all-purpose flour and whisk constantly for about 1–2 minutes until golden.

Add Dairy: Gradually pour the warm whole milk into the roux while whisking continuously, then stir in the heavy cream. Whisk until thick and smooth, about 5–7 minutes.

Melt the Cheeses: Lower the heat and slowly incorporate the sharp cheddar, mozzarella, and parmesan cheese into the sauce. Stir until melted and creamy, seasoning with salt and pepper, and optional paprika and garlic powder.

Combine Pasta and Sauce: Gently fold the cooked elbow macaroni into the cheese sauce, ensuring every piece is coated. Mix in optional ingredients like bacon bits or caramelized onions.

(Optional) Bake to Perfection: Preheat the oven to 375°F. Transfer the mac and cheese to a greased baking dish, sprinkle extra cheese and breadcrumbs on top, then bake uncovered for 15–20 minutes. Let rest for 5 minutes before serving.