Baked mac and cheese

How do you make baked mac and cheese? I am using boxed mac and cheese. but how long and at what temp do I put it in the oven for?

baked mac and cheese
Category Salads - Soups - Sidedishes
Sub Category None


Ingredients

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2 boxes mac and cheese (like Kraft or Annie's)
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1/2 stick butter
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3 cups milk
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4 eggs
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2 tablespoons sugar
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2 teaspoons salt
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pepper to taste
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2 cups sharp cheese, grated





Instructions
1)

set the cheese packet that comes with the box of mac and cheese aside. cook macaroni pasta as directed on box. toss macaroni with butter.
2)

mix together milk, eggs, sugar, salt, pepper, and the packet of powdered cheese that comes with the macaroni and cheese box.
3)

layer buttered macaroni and sharp cheese in a 9x13 pan, ending with cheese.
4)

pour milk mixture over macaroni and bake at 350 for about an hour, or until set in center.
Recipe Origin
benny smith-http://www.desktopcookbook.com/recipe.asp?ID=14104

Thanks for the help. Im new to this cause this is my first time at my own house and now im baking and I dont know how to make much