Preheat the oven broiler to high. Lightly grease a small casserole dish or oven safe dish with non-stick spray.
Cook the pasta according to the package instructions. Drain well and set aside.
Melt the butter in a saucepan over medium heat.
Once melted, whisk in the flour until it turns golden brown.
Gradually whisk in the milk. Add in the cheese and continue whisking until the cheese is melted and the sauce is thick, creamy, and smooth. Season with salt and pepper to taste.
Stir 3/4 of the cheese sauce into the pasta.
Place the pasta into the greased baking dish. Top with the remaining cheese sauce.
Place under the broiler until the top is golden brown. (Keep your eye on it so it does not burn.)
Let sit for 2-3 minutes before serving.