In a mixing bowl, combine bread flour and water, then let it sit for 30 minutes.

Add the sourdough starter, salt, olive oil, and pumpkin puree to the flour mixture.

Mix until a rough dough forms, then knead for 10 minutes until smooth and elastic.

Cover the bowl with a damp cloth and let the dough rise for 8 hours at room temperature.

Gently punch down the dough and shape it into a round loaf.

Place the loaf on a baking sheet lined with parchment paper and dusted with cornmeal.

Using a sharp knife, score the top of the loaf to create a pumpkin-like pattern.

Cover the loaf with a damp cloth and allow it to rest for 3 hours.

Preheat the Dutch oven in the oven at 450°F (230°C).

Carefully place the loaf into the preheated Dutch oven, cover with the lid, and bake for 20 minutes.

Remove the lid and bake for an additional 10 minutes until the crust is golden brown.

Let the bread cool on a wire rack for at least 30 minutes before slicing.