To start, combine the wet ingredients. In a large mixing bowl, whisk together the egg, raw organic sugar, and brown sugar until smooth. Next, add the yogurt, melted coconut oil, pumpkin puree, and potato flake sourdough discard or active starter, mixing until well combined.
Once the wet ingredients are mixed, gradually stir in the flour using a rubber spatula until you have a thick batter.
Cover the bowl with plastic wrap and let it sit at room temperature for 8-12 hours to allow fermentation. If your kitchen is warm, the dough will ferment more quickly. Be aware that you do not want to have your bowl too full because the batter will rise up.
Once the bulk fermentation is complete, preheat your oven to 400°F (200°C). Line your muffin pan with parchment paper liners or cupcake liners to ensure the muffins won’t stick.
Prepare the streusel topping. In a small bowl, mix together ,flour, brown sugar, granulated sugar, cinnamon, and pumpkin pie spice. Stir in the melted butter until the mixture forms coarse crumbs. This can be done using a pastry cutter, fork, your hands, or in a stand mixer with the paddle attachment. Set aside until you’re ready to top the muffins.
After your batter has fermented, it’s time to add the final dry ingredients and spices. Stir in the baking soda, baking powder, salt, cinnamon, pumpkin pie spice, and vanilla extract until fully incorporated.
You’ll notice that the batter is full of air bubbles, do not be afraid of mixing the bubbles away, it will rise enough in the oven and you want to be sure all of the ingredients are well incorporated. Make sure to scrape the sides of the bowl to get everything combined evenly.
Spoon the batter into your prepared muffin tins. Using a ¼ cup measuring cup or a ¼ cup portion scoop will give you consistent muffins every time.
Generously sprinkle the crumb topping over each muffin. The streusel will form a beautiful, crunchy layer as the muffins bake.
Place your muffin pan in the preheated oven and turn the temperature down to bake at 375°F for 18-20 minutes, or until a toothpick inserted into the center comes out clean. The muffins should be golden brown on top with a fluffy texture inside.
Let the muffins cool in the pan for about 5 minutes before transferring them to a wire rack to cool completely. This cooling time is crucial to let the muffins set and prevent them from sticking to the liners or falling apart.
Store your muffins in an airtight container for up to three days at room temperature. Store in the fridge for up to one week. Heat them in the microwave for about 10 seconds to warm them up before eating.