To make the pumpkin puree: Preheat the oven to 350°F. Line a baking sheet with parchment and lightly grease the inside of a loaf pan with coconut oil. Stab the pumpkin a few times with a knife (like you would to bake a potato). Place on the baking sheet, and cook for about 1 hour, or until soft when pierced with a knife. Let cool, then cut in half. Scoop out the seeds with a large spoon and compost. Scoop out the flesh from the pumpkin skin.
Meanwhile, place raisins in a glass bowl or dish with the ginger slices and 8 cloves. Pour boiling water over the raisins just to cover. Let stand for at least 1 hour, or overnight, to infuse with the spices.
Add the flax meal to a large bowl with 6 tablespoons warm water. Let stand for 5 to 10 minutes to thicken. Pulse 1 cup oats in a food processor or spice grinder to make a fine flour. Add to the bowl with the flax, then add the starter, pumpkin, and 3/4 cup oats. Stir to combine. Store any leftover pumpkin in a container in the fridge.
Add the coconut oil, cinnamon, ginger, cardamom, salt, nutmeg, and molasses. Stir to combine. Strain the raisins from their soaking liquid (reserve it in a jar as a sweetener for teas) and add them to the bowl.
Add the baking soda and powder, and stir. The batter will begin to bubble slightly.
Pour the batter evenly into the prepared loaf pan. Bake for 45 to 50 minutes, or until golden on the top and a knife comes out clean when inserted in the middle. Let cool completely, then turn the loaf out onto a plate. Insert the remaining cloves along the top and sides of the loaf. Store in an airtight container on the counter for up to 2 days, or up to 1 week in the fridge (the bread is moist, so if your house is warm best to keep it refrigerated the whole time to prevent mold).