In a large bowl, pour in the cool water and sprinkle the active dry yeast on top. Whisk or stir gently to dissolve the yeast, then let it sit for a few minutes to activate. Next, add the pumpkin puree and whisk until the mixture becomes a smooth, orange liquid without any lumps remaining. I always make sure to whisk thoroughly here to avoid any pockets of unmixed puree showing up in the final loaf.

Add the bread flour and fine sea salt to the pumpkin-yeast mixture in the bowl. Stir everything together using a rubber spatula as much as possible, then switch to your hands to squeeze and fold the dough, ensuring all flour is absorbed and the dough is evenly mixed. The dough will be sticky at this point. Cover the bowl with plastic wrap and leave it at room temperature for one hour. After an hour, wet your fingers and perform a series of dough folds: lift the dough from one side and fold it over itself several times, stopping when the dough tightens and resists folding. Cover again and let rise until it increases in volume by about a third, for another 3-4 hours. Pop any large air bubbles you see to keep the bread’s texture even. Finally, transfer the bowl to the fridge to chill and rest for about 12 hours, or overnight.

The next morning, take the chilled dough from the fridge and gently transfer it to a floured work surface. Using floured hands, shape the dough into a tight, round ball by tucking the edges underneath and using the sides of your hands to round it out. Place the shaped dough onto a small square of parchment paper and dust the top lightly with flour. Cover the dough with a tea towel and let it rise at room temperature for 3-4 hours, until it looks puffy and slightly expanded. I always allow the dough sufficient time here so the loaf bakes up light and airy.

Place a 4-6 quart Dutch oven in your oven and preheat to 450°F (230°C). Once the oven is hot, let the Dutch oven continue heating inside for another 10 to 20 minutes to ensure it's thoroughly preheated. Meanwhile, use a sharp paring knife to score the top of your risen dough with a shallow slash about ½ cm deep (this allows the bread to expand). I find that a quick, confident slash works best for a pretty and controlled loaf split.

Carefully remove the preheated Dutch oven from the oven. Lifting by the parchment paper, transfer the scored dough into the pot, cover with the lid, and bake on the center rack for 20 minutes. Then, remove the lid and continue baking for another 20-25 minutes, until the bread is deeply golden and the crust feels firm to the touch.

Take the baked bread out of the Dutch oven and let it cool on a rack for at least an hour before slicing. This resting time allows the crumb to set and the flavors to fully develop. Personally, I find the bread cuts much more cleanly—and tastes better—when I resist slicing in too soon!