Put the olive oil, butter, and garlic in a wide, deep pot over medium heat, and cook, stirring, until the garlic is fragrant, but not brown. Add the wine and the clams, and cover. Turn the heat up to medium-high and steam until the clams start to open, about 5 minutes. Add the mussels, cover and steam until the just start to open, about 2 minutes.
Now stir in the cioppino sauce, the Worcestershire sauce and saffron and bring to a simmer. Add the cracked crabs, if using, and the shrimp, and simmer for about 5 minutes.
Then gently stir in the fish, squid and scallops, and simmer until they are all just cooked through, about 5 minutes. (If using cooked crab meat, stir it in very gently the last minute or so of cooking time.)
For the Cioppino Sauce:
Heat the olive oil in a large saucepan over medium heat. Add the onions and sauté until translucent. Add the garlic, bay leaves, parsley and basil and cook, stirring, just to warm the garlic—do not let it brown.
Stir in the crushed tomatoes, tomato puree, water, clam base, brown sugar, celery salt, Worcestershire sauce, black and red peppers, cinnamon and salt to taste. Bring to boil, reduce heat to low-medium and simmer uncovered for about 1 hour and 15 minutes, stirring occasionally, until thickened.
You can make the cioppino sauce up to three days prior, and keep it in a sealed container in the fridge.