Blend together the salt, pepper, sugar, and mustard powder; set it aside. Next, boil elbow macaroni noodles according to the package directions. Drain and pour into the baking dish with butter and half the spice mix. Coat the noodles well then toss in cubes of mild cheddar cheese or any kind of cheese you prefer.
Whip softened cream cheese in a mixing cup until smooth and creamy. Add eggs and mix until pale yellow and liquid.
In a pot pour the egg mixture into the half and half. Turn the pot to low heat and add the butter, cheese, and remaining spice mix. Allow cheeses to melt stirring constantly. The cheese sauce should resemble a thin custard. Remove from the heating surface.
Immediately pour the cheese sauce over noodles and cheese cubes. Stir to mix well. Bake uncovered for 45 minutes. The sauce will be absorbed by the noodles and the top will be a golden brown. Let it sit until firm for 10-15 minutes.
Be sure to assemble and bake on a cookie sheet because the cheese sauce may overflow a little.