Joy of Cooking's Baked Macaroni and Cheese / Macaroni et Fromage au Four de Joy of Cooking

This recipe for baked macaroni and cheese comes from "The Joy of Cooking" (the 75th Anniversary Edition) by Irma S. Rombauer, Marion Rombauer Becker, and Ethan Becker. I've altered the measurements of some of the ingredients slightly because I like my mac and cheese extra cheesy with more onion and paprika than the original recipe.

Ingredients
2 cups macaroni (elbows, wheels, corkscrews, bowties, etc.)
3 tablespoons butter, divided (plus extra for greasing the pan)
2 tablespoons flour
2 cups milk
1 onion, chopped
1 bay leaf
1 teaspoon paprika
3 cups grated sharp cheddar cheese, divided
1/2 cup fresh bread crumbs

Directions
1. Cook the macaroni in the water until it is just tender, then drain it and put it a bowl.
2. Melt 2 tablespoons of the butter in a large pot.
3. Add in the flour and cook, whisking constantly, for about 3 minutes.
4. Gradually whisk in the milk.
5. Stir in the onion, bay leaf, and paprika and simmer, stirring often, for about 15 minutes (until the onions are soft).
6. Remove the pot from the heat, take out the bay leaf, and stir in 2 cups of the cheese.
7. Stir in the macaroni.
8. Pour half of mixture into a greased (with your extra butter) baking dish and sprinkle it with half of the remaining cheese. Then layer on the rest of the macaroni and the rest of the cheese.
9. Melt the last tablespoon of butter in small skillet over medium heat, stir in the bread crumbs so they get coated with melted butter.
10. Sprinkle the buttered bread crumbs over the top of the macaroni and cheese.
11. Bake the macaroni and cheese at 350 degrees Fahrenheit, until the bread crumbs are lightly browned. This should take about 30 minutes.
12. You're supposed to let this dish stand 5 minutes before serving, presumably to prevent you from burning your mouth, but I can never wait that long.