Cook the elbow macaroni in boiling water until al dente.
Drain the macaroni and add it to the crockpot.
In a separate bowl, mix together the melted butter, milk, sour cream, garlic powder, onion powder, salt, and pepper.
Stir in the shredded cheeses until well combined.
Pour the cheese mixture over the macaroni in the crockpot.
Stir well to combine all ingredients evenly.
Cover and cook on low for 2-3 hours, or until cheese is melted and bubbly.
Stir occasionally during cooking to prevent sticking and ensure even melting.
Once done, serve hot and enjoy your creamy mac and cheese!