Add all but the bacon, onion, and crackers to a medium mixing bowl. Peel and coarse-chop the onion and add it to the bowl. If using crackers, put them into a gallon plastic food bag, and roll with a rolling pin till the crackers are fine crumbs. Add the cracker crumbs or bread crumbs to the mixing bowl. Don’t mix what’s in the bowl yet, just set it aside.
Preheat an oven to 250F. Grease a small cooking rack and set it in a roasting pan, deep casserole, or enamel pot. Lay two slces of bacon next to each other in the middle of the rack.Lay the other slices perpendicular to the first two, five on each side, side-by-side, with the inside end at the far side of the first two slices. If you have more than these twelve slices of bacon, add four more slices, two on each end, to extend the length of original two slices.
Use your hands (with food-handling gloves if desired) to fully mix the meat mixture. Form it into a loaf, which will be about 7 inches long and just over 3 inches in diameter. Lay the loaf in the middle of the bacon over the first two slices. Then, pick up the rest of the bacon piece-by-piece and fully wrap the loaf.
Bake in the 250F oven for three hours or until a meat thermometer inserted into the center of the loaf reads 160F. Then go ahead and bake it for one more hour to crisp the bacon.
Remove the loaf from the oven and allow it to rest before slicing with a serrated knife and serving.