Whisk the eggs in a large bowl until frothy. Combine the Velveeta, butter, and one and half cups of the half-and-half in a large bowl.
Add the warm macaroni, tossing until the cheese has melted and the mixture is smooth. Add the remaining ingredients (keeping 1/2 cup of yellow cheddar aside). Mix well (I suggest using your hands to make sure all ingredients are well combined - my kids love to help with this step also!).
Pour the mixture into a 9 x 13-inch casserole or baking dish and bake for about 30 minutes at 350 degrees. Sprinkle with the remaining 1/2 cup of sharp yellow cheddar cheese and bake until golden brown on top, about 30 minutes more. Serve hot.