This is a modified version of a recipe I found a few years back in a magazine (don't recall which). My children love this and ask for it often and it is so easy to do that my young teen-ager can throw it together alone.
Cook macaroni noodles (or other favorite style) in boiling, salted water until barely aldente; do not overcook as you still have many hours of cooking time; Note: salting your pasta water is the only time you can actually season the pasta itself; it really does make a difference in flavor.
Place 1/2 cup butter into bottom of crockpot.
After draining the pasta well, toss it into crockpot and mix with the butter; the heat of the fresh pasta will melt the butter.
In a seperate bowl, blend together the evaporated milk, cheddar soup, and cup of milk; blend into pasta.
Toss in 3 cups of shredded cheddar cheese, holding the last cup to side as topping ( I often mix cheddar and colby for a different flavor and sometimes parmesian if I have extra on hand).
Cook in crockpot on high for 4 hours or low for 6 hours.
Add last cup of cheese on top last 30 minutes or so to allow to melt.