Preheat the oven to 350 degrees F (175 degrees C). Spray a 12-cup muffin tin with cooking spray.
Combine beef, tomatoes, bread crumbs, egg substitute, 3 tablespoons ketchup, dried onion, Worcestershire sauce, salt, and pepper in a bowl. Fill muffin cups with the beef mixture.
Mix remaining 1 tablespoon ketchup with brown sugar and vinegar in a small bowl to create a glaze. Brush or spoon glaze over the muffins.
Bake in the preheated oven until muffins are no longer pink in the center, about 35 minutes. An instant-read thermometer inserted into the center should read at least 160 degrees F (70 degrees C).
