Position a rack in the center position of the oven.
Preheat the oven to 350 degrees F.
In a large pot of boiling water, add the head of cabbage.
Reduce the heat to low and cover the pot.
Allow the cabbage to simmer until just tender, about 10 minutes.
Carefully transfer the cabbage, cored-side down, to a plate and allow it to cool.
In a large skillet over medium-high heat, add the olive oil and heat until it is shimmering.
Add the ground beef, the sausage, and the onions to the hot oil and cook, while crumbling the meat with a wooden spoon, until the meat is no longer pink and the onions are softened, about 8 minutes.
Add the garlic, the salt, and the black pepper to the beef mixture and cook, while stirring, until fragrant, about 2 minutes.
Transfer the skillet from the heat.
Add the rice and the tomato paste to the beef mixture and stir to combine.
Peel the leaves from the cooled cabbage, being careful to keep the leaves whole and intact, and lay them flat on a clean work surface.
Add about 1/2 cup of the beef mixture down the center of each of the cabbage leaves.
Fold in the sides then roll the cabbage leaves up so they cover the beef mixture.
In a 9x13-inch baking dish, add the cabbage rolls in a single layer.
Brush the tops of the cabbage rolls with the ketchup.
Lay the bacon over the top of the cabbage rolls in a single layer.
Cover the baking dish with foil.
Bake the cabbage rolls for 30 minutes.
Remove the foil and bake until the bacon is crisp, about 15 minutes.
Serve.