Prep Your Starter: The night before baking, feed your sourdough starter to ensure it's bubbly and active by the next morning. When ready, it should pass the float test: a small spoonful of starter should float in water.
Mix the Dough: In a large mixing bowl, combine 100g of active sourdough starter, 180g of warm water, and 200g of pumpkin purée. Stir until smooth, then gradually add 500g of flour. Mix until the dough begins to form, then add the maple syrup, salt, and a pinch of nutmeg and turmeric. Use your hands or a Danish dough whisk to fully incorporate the ingredients.
Autolyse and Rest: Cover the dough and let it rest for 60-90 minutes. This period, called the autolyse, helps hydrate the flour and begins the gluten development process.
Stretch and Fold: Perform a series of three stretch-and-folds, spaced 30 minutes apart. After the third fold, gently stretch the dough into a rectangle on a lightly floured surface.
Add the Filling: Spread the cinnamon-sugar filling evenly across the dough. Fold the dough over itself, forming a loose ball, and return it to a proofing basket.
Shape and Rise: Shape the dough into a round loaf. Place it in a lightly floured proofing basket, cover with a tea towel, and let it rise overnight. If your kitchen is cool, leave it out at room temperature; otherwise, refrigerate the dough for a slower rise.
Shape the Pumpkin Loaf: The next day, turn the dough out onto a piece of parchment paper. Lay out baking twine in a crisscross pumpkin pattern, gently place the dough in the center, and loosely tie the strings around the loaf to create a pumpkin shape.
Bake the Loaf: Preheat your oven to 450°F with a Dutch oven inside. Score the dough with shallow cuts on top, then transfer it (on the parchment paper) into the preheated Dutch oven. Cover and bake for 30 minutes, then remove the lid and bake for another 10-15 minutes, until the loaf reaches an internal temperature of 210°F and the crust is golden brown.
Cool and Enjoy: Allow the bread to cool on a cooling rack for at least 10 minutes before slicing. Serve with a spread of butter or cream cheese for extra indulgence!