Preheat your oven to 375°F (190°C).
Blanch the cabbage leaves in boiling water for 2-3 minutes or until soft. Drain and set aside.
In a bowl, mix the ground beef, onion, rice, egg, garlic powder, paprika, salt, and pepper.
Take a cabbage leaf, place a portion of the meat mixture in the center, and roll it up, tucking in the ends. Repeat with the remaining leaves.
Place the rolls seam side down in a baking dish.
In a separate bowl, mix the tomato sauce, brown sugar, lemon juice, and Worcestershire sauce. Pour this sauce over the cabbage rolls.
Cover with foil and bake for about 1 hour, or until the meat is cooked through.