Prepare the Cabbage
Bring a large pot of salted water to a boil. Carefully cut the core out of the cabbage and separate the leaves, being careful not to tear them. Place the cabbage leaves into the boiling water for 3-5 minutes until they soften and become pliable. Drain and set aside to cool.
Cook the Beef Filling
In a large skillet, heat a tablespoon of olive oil over medium heat. Add the chopped onion and garlic, cooking until softened and fragrant, about 3-4 minutes. Add the ground beef and cook until browned, breaking it up with a spoon. Drain any excess fat.
Season the Beef
Stir in the cooked rice, oregano, paprika, salt, pepper, red pepper flakes (if using), and parsley. Mix everything together and let it cook for another 2-3 minutes. Taste and adjust the seasoning if needed.
Assemble the Cabbage Rolls
Lay a cabbage leaf flat on a clean surface. Spoon about 2-3 tablespoons of the beef and rice mixture into the center of the leaf. Fold the sides of the leaf over the filling, then roll it up tightly, securing the ends. Repeat with the remaining cabbage leaves and filling.
Prepare the Sauce
In a medium bowl, mix the tomato sauce, crushed tomatoes, brown sugar (if using), and lemon juice (optional). Stir well to combine.
Bake the Cabbage Rolls
Preheat your oven to 350°F (175°C). Spread a thin layer of the tomato sauce mixture in the bottom of a baking dish. Arrange the cabbage rolls in the dish, seam side down. Pour the remaining sauce over the top of the rolls, covering them completely. Cover the dish with aluminum foil.
Bake
Bake the cabbage rolls in the preheated oven for 45 minutes. After 45 minutes, remove the foil and bake for an additional 15 minutes to allow the sauce to thicken and the rolls to brown slightly on top.
Serve
Remove the cabbage rolls from the oven and let them rest for a few minutes before serving. Enjoy the tender, flavorful cabbage rolls with a side of crusty bread or a fresh salad.