In a large bowl, mix the starter, pumpkin, water and maple syrup until loose. Add the flour and cinnamon and mix until no dry flour remains. Cover and rest 30 minutes.

Sprinkle the salt over the dough and squeeze it in with wet hands, then fold the dough over itself for 1 to 2 minutes.

Over the next 2 hours, do 4 sets of stretch and folds, 30 minutes apart. Then leave the dough covered until it has grown about 50% and looks puffy with bubbles on the sides, usually 4 to 6 hours total at 75°F.

Turn the dough onto a lightly floured counter and shape it into a tight round. Place it seam-side up in a floured banneton or towel-lined bowl.

Cover and refrigerate 8 to 16 hours.

Heat the oven to 475°F (245°C) with a Dutch oven inside for 45 minutes.

Oil 4 long pieces of kitchen twine. Turn the cold dough onto parchment, then lay the strings under and over it so they cross at the top and form 8 sections. Tie loosely, leaving room for the loaf to expand.

Lower the loaf into the Dutch oven, cover, reduce heat to 450°F (230°C) and bake 25 minutes. Uncover and bake 20 to 25 minutes more, until deep golden and 205 to 210°F (96 to 99°C) inside.

Cool 10 minutes, carefully snip and remove the twine, press a cinnamon stick into the top and cool at least 1 hour before slicing.