Cook the elbow macaroni according to package instructions until al dente.
Drain the macaroni and set aside.
In a large bowl, combine cooked macaroni with cheddar cheese, mozzarella cheese, and cheddar cheese soup.
Add milk, sour cream, garlic powder, onion powder, salt, and pepper. Mix well.
Transfer the mixture to the crock pot, spreading it evenly.
Cover and cook on low for 2-3 hours or on high for 1-1.5 hours.
Stir occasionally to ensure even cooking.
If desired, sprinkle breadcrumbs on top during the last 30 minutes.
Once cooked, serve hot and enjoy!