Lay the bread cubes in a single layer on two baking sheets. Leave out to dry completely at room temperature, tossing once or twice, for about 2 days.

Position a rack in the center of the oven and heat the oven to 375 degrees F.

In a heavy-based, 8-quart stockpot or Dutch oven, melt 5 tablespoons of the butter over medium heat until it begins to foam. Stir in the thyme, sage, and poultry seasoning and cook just enough to coat the herbs and season the butter, 30 to 60 seconds. Stir in the onions and celery and cook, stirring occasionally, until soft and fragrant, about 15 minutes. Add the chicken broth, bay leaves, and ham hock and bring to a boil over high heat. Reduce the heat to medium low and simmer until the liquid reduces by one-third, about 30 minutes.

Meanwhile, put the sausage on a rimmed baking sheet and break it into quarter-size chunks. Roast until cooked through, about 15 minutes. Let cool, and then chop the sausage into smaller bits.

Add the sausage to the broth and simmer just to allow the flavors to meld, about 5 minutes. Remove the ham hock and bay leaves. Discard the bay leaves and set the hock aside to cool. Stir the dried bread, several cups at a time, into the broth until all of the broth is absorbed and the bread cubes are well moistened. Stir in the maple syrup, pepper, and the remaining 5 tablespoons butter.

When the hock is cool enough to handle, pick off the meat, chop it into small pieces, and add to the stuffing. Season to taste with salt if necessary (depending on the sausage and ham hock, both of which are salty, there may already be enough).

Transfer the stuffing to a 9x13-inch baking dish and bake uncovered at 375 degrees F until heated through and crisp on top, about 20 minutes if freshly made, or about 30 minutes if made ahead.

The bread can be dried weeks in advance, bagged, frozen, and then thawed when ready to use. The stuffing can be made (but not baked) up to 2 days ahead and refrigerated, covered.