Tear the leaves off the cabbage and cook in boiling water or steam until wilted enough to be flexible. Cool. Mix ground beef, rice, egg, onion, and salt, pepper, and 1/2 teaspoon of cinnamon together.
Form a few tablespoons of the mixture into a cylinder, then roll up in a cabbage leaf. Secure rolls with toothpicks. Combine the soup and tomatoes in a Dutch oven. Place cabbage rolls in the Dutch oven. Sprinkle with about 1/2 teaspoon of cinnamon. Cover and simmer for 1 1/2 to 2 hours.