Brown the ground beef in a skillet and drain excess fat.
Add the browned beef, onion, green bell pepper, tomato sauce, ketchup, brown sugar, Worcestershire sauce, garlic powder, mustard, salt, and pepper to the crockpot.
Stir to combine all ingredients and cook on low for 4 hours.
Serve the mixture on soft buns.
Notes
You can adjust the seasoning to your taste and add different toppings if desired.