Step 1: Preheat the oven to 350 degrees F
Step 2: Bring a large pot of lightly salted water to a boil. Cook elbow macaroni in the boiling water, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain and set aside.
Step 3: Melt butter in a large saucepan over medium heat. When butter starts to melt, stir in flour; cook on medium heat until flour begins to turn pale yellow, 3 to 4 minutes. Add seasonings then cook and stir another minute. Next whisk in milk until smooth. Bring sauce just to a simmer until thickened (about 5-8 minutes)
Step 4: Turn heat off, then add cheddar and parmesan cheeses; stir until melted and combined. Mix in jarred pasturized cheese.
Step 5:, Drain macaroni noodles then pour in cheese sauce; stir to thoroughly combine.
Step 6: Sprinkle remaining 3/4 cup Cheddar cheese on top. Bake in the preheated oven until top is golden brown, about 20-30 minutes.