How to Make It
Heat oven to 375 degrees F.
Cook macaroni in a large pot of salted boiling water until tender but not mushy, about 8-10 minutes. Drain well and pour into a large mixing bowl.
Working over low heat, melt the Velveeta cheese with 3/4 cup milk, stirring constantly.
Pour melted cheese sauce over pasta and stir. Add butter, ¾ cups milk, eggs, 1/2 cup each shredded cheeses, and salt and pepper. Mix well and transfer to a 2-quart baking dish. Sprinkle the remaining cheese on top.
Bake until crust is golden brown and casserole is bubbling, about 25 minutes. Serve hot.