Heat a large skillet over medium-high heat and add a tablespoon of vegetable oil. Add the ground beef, seasoning it with salt and pepper. Cook for 6-8 minutes until browned, breaking it apart with a wooden spoon.

Drain excess grease from the skillet and transfer the browned beef to the slow cooker.

In the slow cooker with the beef, add the tomato sauce, ketchup, brown sugar, Worcestershire sauce, garlic powder, onion powder, mustard, and smoked paprika. Stir until combined.

Cover and cook on HIGH for 3 hours or LOW for 6 hours until bubbly.

Scoop portions of the mixture onto hamburger buns and top with yellow cheese slices if desired.