Modified from Cook's Country
8 oz (2 cups) cheddar cheese, shredded (divided)
4 oz (1 cup) American cheese, shredded
4 tsp cornstarch (divided)
8 oz (2 cups) dry elbow macaroni
1 cup heavy cream (I didn't have this, used half and half and it was fine)
2 cups water (because of the above, I did like 1 1/2 cups water, 1/2 more half and half)
2 eggs
2 tsp Dijon mustard
2 tsp hot sauce (so I didn't use this much...I did a few dashes of it)
2 tsp Worcestershire sauce
1/2 tsp salt (who measures this? I did add a little, but not much since cheese is so salty)
1/2 tsp pepper (I did pepper this well, but I didn't measure)
Preheat oven to 400. Toss 4 oz cheddar, American cheese and 2 tsp cornstarch in a bowl. Add in macaroni (this is NOT pre-cooked!) and toss to combine. Put into a 8 inch baking dish (I did Pam it).
Whisk cream and rest of cornstarch until the cornstarch is dissolved. Whisk in rest of ingredients (other than the rest of the cheddar). Pour over macaroni mixture. Cover with foil and bake for 30 minutes.
Remove from oven and stir well (you are mixing up the pasta). Sprinkle with rest of cheddar. Return, uncovered, to the oven and bake for 15 more minutes or until center is 150-160 and edges are set and bubbly.
They said to broil it...I didn't as my top was already pretty well browned. Let rest for 25 minutes before serving.
Serves 4-6.