Start by cooking the elbow noodles according to the package directions for al dente. When the noodles are done, drain and place them in your lined slow cooker. Add the butter and mix well. Then, in a large bowl, mix 3 cups of the cheese with the evaporated milk, milk, eggs, and condensed soup until well combined. When the mixture is ready, pour over the noodles and stir to combine. To cook, cover and set the temperature on LOW for 3 ½-4 hours. When a food thermometer reads 160°, sprinkle the remaining cheese on top and allow to cook a little longer until the cheese is melted. Before serving, sprinkle with paprika. Enjoy!