Bring a pot of water to a boil over medium high heat. Cut the onions halfway through the center and boil for 15 minutes until they start to slightly soften.
Remove the onions from the water and let them cool for a few minutes. Remove the first 4-5 layers of each onion to make dolma and chop the inner ones and set aside. You can use some of the chopped onion in the filling if desired.
Make the filling by mixing rice, ground beef, garlic, parsley, mint, Aleppo pepper, allspice, oregano, salt, pepper, tomato paste, pepper paste, pomegranate molasses, and olive oil in a bowl.
Preheat the oven to 375 degrees F.
Fill each onion layer with 1 to 1 1/2 tablespoon filling, gently roll it up so the ends overlap and nestle tightly next to each other in a baking dish (ceramic).
Make the sauce by mixing the tomato paste with hot water, pomegranate molasses, olive oil, salt and pepper. Pour over the dolmas and cover with aluminum foil.
Bake for 45 minutes. Then, uncover and bake for another 30 minutes until the sauce is reduced and the onions are golden. The stuffed onions are ready once the onions are tender and the filling is fully cooked.