In a large pot, cook the macaroni in boiling water 10 minutes, or until al dente, and drain.
In a large bowl, mix the cooked macaroni, 3 cups of the sharp Cheddar cheese, evaporated milk, milk, eggs, salt, and pepper. Transfer to a slow cooker that has been coated with non-stick cooking spray. Sprinkle with the remaining 1 cup of shredded sharp Cheddar cheese.
Cover, and cook on Low for 5 to 6 hours, or until the mixture is firm and golden around the edges. Do not remove the cover or stir the mixture until the mixture has finished cooking. Serve warm.