Cook the elbow macaroni according to the package instructions until it’s just shy of being fully cooked (al dente). Drain and set aside.
In a large mixing bowl, combine the shredded sharp cheddar cheese, shredded mozzarella cheese, and grated Parmesan cheese.
Layer one-third of the cooked macaroni in the bottom of your slow cooker.
Add one-third of the butter pieces and one-third of the mixed cheese.
Repeat the layering process two more times until all the macaroni, butter, and cheese are in the slow cooker.
In a separate mixing bowl, whisk together the whole milk, evaporated milk, salt, black pepper, paprika, garlic powder, and onion powder.
Pour the milk mixture over the macaroni and cheese layers in the slow cooker.
Cover the slow cooker and cook on low for 3-4 hours, or until the mac and cheese is hot and bubbly, and the cheese is fully melted.
Stir the mac and cheese well before serving to ensure a creamy consistency.