Prepare the slow cooker:
Lightly grease your slow cooker insert with nonstick spray or butter to prevent sticking and make cleanup a breeze.
Add ingredients:
Pour the uncooked elbow macaroni into the slow cooker. Add the melted butter, whole milk, evaporated milk, Velveeta cubes, shredded cheddar, and all the seasonings — salt, black pepper, garlic powder, dried mustard powder, and paprika.
Stir to combine:
Mix everything gently until the pasta is evenly coated and the cheese begins to blend with the milk and butter. The sauce will look thin at first — but trust the process. The magic happens as it cooks!
Cook on low:
Cover and cook on LOW for 2½ to 3 hours, stirring once or twice throughout to ensure the cheese melts evenly and the pasta cooks uniformly. Every slow cooker is different, so check around the 2-hour mark. The pasta should be tender but not overdone, and the sauce should be creamy and smooth.
Adjust consistency and serve:
Once done, give it a final stir. If the sauce seems too thick, add a splash of milk to loosen it up. If it’s too thin, let it cook uncovered for an additional 10–15 minutes until it reaches your perfect creamy texture. Sprinkle with a little extra cheddar or paprika before serving for that golden, cheesy finish.