Easy Crock Pot Sloppy Joes

Name: Easy Crock Pot Sloppy Joes
Prep time: 15 min
Cook time: 4 h
Total time: 4 h 15 min
Cuisine: American
Ingredients: 2 pounds ground beef (or turkey!); 1/2 cup chopped onion; 1 tsp. garlic powder; 2 tsp. prepared yellow mustard; 1 1/2 cups ketchup; 2 Tbsp. light brown sugar; 2 tsp. salt; 1/2 tsp. ground black pepper; hamburger buns; cheese (for serving)