01 -
Cook the elbow macaroni in boiling salted water according to the package directions until al dente. Drain thoroughly.
02 -
In a large skillet over medium heat, melt the butter, then add shredded Cheddar and Mozzarella cheeses. Stir continuously until both cheeses are fully melted and blended with the butter.
03 -
Transfer the melted cheese and butter mixture, cheddar cheese soup, and sour cream to the slow cooker crock. Add the drained macaroni, milk, salt, mustard powder, and paprika. Mix thoroughly to ensure an even distribution of all ingredients.
04 -
Cover and cook on low heat for 2 hours, stirring halfway through, until the mixture is hot and creamy.
05 -
Stir well before serving. Portion while hot for best texture.