Steam the pumpkin for 20–25 minutes. Alternatively, microwave it in a suitable container covered with plastic wrap for about 15 minutes. Let it cool slightly. Blend it with the water.

Add the pumpkin puree to the flour mixed with the yeast, sugar, and salt. Add the olive oil and knead everything together. The dough will be sticky. Place it in a bowl and let it rise for 2 hours at room temperature or for 12 hours in the refrigerator.

Turn the dough out into the baking pan and let it rise for another hour. If you let it rise in the fridge, to bring the dough to room temperature, place it in the pan and start gently stretching it. Let it rest for 30 minutes. Now spread it evenly to cover the whole pan and let it rest for another 40 minutes.

Meanwhile, preheat the convection oven to 350°F (180°C). Add the Taggiasca olives and rosemary, pressing them into the dough with your fingers dipped in a mixture of water and olive oil. Sprinkle with flaky sea salt and bake for 30 minutes.