12 ounces dried elbow macaroni pasta
1/4 cup unsalted butter, room temperature
1/4 cup all-purpose flour
1 1/2 cups milk
1 cup light cream
1/2 teaspoon dry mustard powder
1 teaspoon onion powder
1 can (10.75 ounces) condensed cream of cheddar soup
4 cups shredded cheddar cheese, divided
1/2 cup shredded Parmesan cheese
Kosher salt and fresh ground black pepper
Heat the oven to 425 F. Spray a deep baking dish with non-stick cooking spray, and set aside.
Cook macaroni pasta in salted, boiling water according to package instructions for "al dente," about 8 minutes.
Drain pasta and rinse under cold water to stop the cooking process. Drain again and set aside.
Heat a large saucepan over medium-high heat.
Add butter and melt. Add flour, and combine to form a roux. Cook until the roux is light brown in color, about 2 minutes.
Slowly whisk in the milk, cream, dry mustard, onion powder, salt, and pepper (to taste), until fully combined.
Cook over medium heat until thickened, about 4 to 6 minutes.
Turn heat to low and add cheddar soup, Parmesan cheese, and 3 cups of cheddar cheese.
Stir together until the cheese is melted and the sauce is fully combined.
Add cooked macaroni to the saucepan and toss in the cheese sauce until fully coated.
Transfer the pasta into the prepared baking dish and spread it out evenly. Top with the remaining cheddar cheese.
Place the baking dish in the oven and allow pasta to bake until golden brown on top and bubbling around the edges, about 20 to 25 minutes.
Remove the casserole from the oven and allow to cool for 5 to 10 minutes.