Instructions

• Bring a large pot of salted water to a boil. Add 14 oz dry elbow macaroni and cook to al dente according to the package instructions. Before draining, reserve 1/2 cup of the pasta cooking water; then drain the pasta and set it aside.
• While the pasta is cooking, melt 3 1/2 Tbsp butter in a medium saucepan (about 4-quart) over medium heat.
• Add 3 1/2 Tbsp flour to the melted butter and cook for 1 minute, whisking constantly to form a roux.
• While whisking constantly, slowly pour in 2 1/3 cups low-fat milk. Whisk in 1/2 tsp dry mustard and 1/4 tsp garlic powder. Increase the heat slightly and continue whisking until the mixture reaches a gentle simmer and begins to thicken. Do not let it boil.
• Reduce the heat to low and add 4 oz cream cheese (diced); whisk until the cream cheese is fully melted and the sauce is smooth.
• Remove the saucepan from the heat. Add the shredded cheeses (8 oz extra-sharp cheddar and 4 oz mozzarella) in two additions: add half of each, whisk to melt, then add the remaining half and whisk until the sauce is smooth. If needed to finish melting the cheese, return the pan briefly to low heat while whisking constantly; avoid boiling the sauce.
• Season the cheese sauce with salt to taste.
• Add the drained pasta to the sauce and toss to coat evenly. If the sauce is too thick, thin it with the reserved pasta water a splash at a time until you reach the desired consistency.
• Serve immediately.