In a large bowl or the bowl of a stand mixer with the whisk attachment, combine the brown sugar, eggs, potato flake starter, pumpkin puree, and melted coconut oil. Mix on low speed until the ingredients are combined.
If you’re using a hand mixer or mixing by hand with a hand whisk, make sure the ingredients are well incorporated.
Once the wet ingredients are mixed well, add in the all purpose flour. Mix until well combined.
Once mixed, cover the bowl with plastic wrap. Let it sit in a warm place for 8-12 hours to allow the dough to ferment. The dough might rise, but it might not double in size. It might develop bubbles on the top, indicating that the fermentation process is taking place.
Once the dough has fermented, preheat your oven to 350°F. Add the remaining dry ingredients: salt, baking soda, baking powder, pumpkin pie spice, cinnamon, and vanilla. Use the paddle attachment on your stand mixer (or a silicone spatula if mixing by hand) to mix the ingredients on low speed until fully combined.
Line a 5x9 loaf pan with parchment paper or grease it well to prevent sticking. If you have smaller loaf pans, feel free to use them, but adjust the cooking time accordingly. For smaller mini pans, bake for 25-30 minutes, while a regular-sized loaf pan will take 55-65 minutes.
Before baking, sprinkle 3 tablespoons of pepitas over the top of the batter. The pepitas will add a nice crunch and nutty flavor that complements the rich, spiced pumpkin bread.
Bake your bread for 55-65 minutes. After 45 minutes, check the top of the loaf—if it’s browning too quickly, loosely cover it with foil. This prevents the top from burning while the inside finishes baking.
The best way to check if the bread is done is to use an instant thermometer. The internal temperature should read between 195-205°F. Alternatively, you can use a toothpick—insert it into the center of the loaf, and if it comes out clean, the bread is done.
Once the bread has finished baking, let it cool in the pan for about 20 minutes. Then, carefully transfer it to a wire rack to cool completely. Waiting for the bread to cool helps it firm up, making it easier to slice.
Once your bread is fully cooled, store it in an airtight container to keep it fresh. It’s best enjoyed within 2-3 days, but it can also be frozen for longer storage.