Pioneer Woman's Baked Mac & Cheese

4 c. uncooked macaroni
4 tbsp. butter
1/4 c. all-purpose flour
2 1/2 c. whole milk
2 tsp. dry mustard
1 egg, beaten
1 lb. cheese, grated (any variety/combination)
1/2 tsp. salt
1/4 tsp. garlic powder
1/4 tsp. onion powder
1/2 to 1 tsp. ground black pepper
Dashes of cayenne, paprika, and thyme (optional)

Preheat the oven to 350°F. Cook macaroni according to package directions until slightly firm. Drain and set aside.

In a large pot, melt butter over medium-low heat. Whisk in flour and cook mixture for five minutes, whisking constantly and being careful not to burn. Add milk to pot, stir in dry mustard, and whisk until smooth. Cook mixture for five minutes until very thick. Reduce heat to low.

Add beaten egg to a small bowl. Take 1/4 c. warm sauce and slowly pour it into the beaten egg, whisking constantly to avoid scrambling the egg. Whisk until smooth. Pour tempered egg mixture back into sauce, whisking constantly. Stir until smooth. Mix in cheese, reserving a handful for topping, and stir until completely melted. Add salt and other seasonings. Taste and adjust seasonings accordingly. Add drained cooked macaroni to pot and mix well.

Pour mixture into a baking dish, top with reserved cheese, and bake for 20 to 25 minutes or until golden and bubbly on top.