02Bring a large sauce pan of salted water (pinch of salt) plus ½ tablespoon of olive oil to a boil. Add the macaroni and cook until al dente (about 10 minutes); drain and set aside to keep warm.
03Whisk the eggs in a large bowl until frothy. Combine the melted or soft Velveeta, butter, and 1 cup of the half-and-half in a large bowl. Add in each cheese, except one cup of yellow cheddar, mixing well. Add the warm macaroni and toss until the cheese is melted and the mixture is smooth. Add the remaining half-and-half, salt and pepper, tossing until completely combined.
04Pour the mixture into a 4x6 inch casserole or baking dish and bake for 30 minutes. Sprinkle the remaining 1 cup of yellow cheddar cheese and bake until golden brown on top, about 20 minutes more. Serve hot.