In a large mixing bowl, combine the pumpkin puree, warm water, and active sourdough starter. Stir until well mixed.

In a separate bowl, whisk together the bread flour, salt, honey, cinnamon, nutmeg, ginger, and allspice.

Gradually add the dry ingredients to the wet ingredients, stirring until a shaggy dough forms.

Knead the dough on a lightly floured surface for about 10 minutes until smooth and elastic.

Place the dough in a lightly greased bowl, cover with a damp cloth, and let it rise in a warm place for about 4-6 hours, or until doubled in size.

Once the dough has risen, gently deflate it and shape it into a round loaf. Place it on a parchment-lined baking sheet.

Cover the loaf with a cloth and let it rise again for about 1-2 hours, or until puffy.

Preheat the oven to 450°F (230°C). Place a shallow pan of water on the bottom rack to create steam.

Score the top of the loaf with a sharp knife and bake for 30-35 minutes, or until the crust is golden brown and the loaf sounds hollow when tapped on the bottom.

Allow the bread to cool on a wire rack before slicing.