For cabbage rolls: Bring a large pot of salted water to a boil, add cabbage leaves, cook until tender about 4 minutes. Drain and rinse with cold water, set aside.
In a large bowl combine beef, pork, sour cream, rice and 2 tspn. salt.
Heat 2 tbsp. butter in a medium size skillet over medium heat. Add onion, garlic, paprika and allspice. Cook until onions are soft about 7 minutes. Let cool.
Add cooled onion mixture to beef mixture and combine well. Season with pepper to taste.
Lay cabbage leaves on a work surface and blot dry with a paper towel. Slice off the ridged part of the thick rib at the bottom of each cabbage leaf. Place about 1/2 cup of the mixture in the bottom center of each leaf. Roll the bottom of the leaf over the mixture, fold in the sides, and continue rolling forward until completely closed (like your rolling up a burrito). Repeat with the remaining leaves. Arrange rolls seam side down in a 9-x 13-x 2-inch baking dish.
For tomato sauce: Heat 1 tbsp butter in a medium skillet over medium heat. Add onions and garlic, cook until soft about 7 minutes. Add tomato sauce, chicken broth, tomato soup, bay leaf, brown sugar, salt and pepper. Bring to a boil and reduce to a simmer. Add the cream. Pour sauce over the cabbage rolls and cover tightly with foil. Bake for 1 hour.
Remove the foil and continue cooking, basting occasionally, until lightly browned and cooked through, about 30 minutes more.