• Preheat the oven to 350 degrees F and grease or line a 9x5 inch loaf pan with parchment paper.
• In a large bowl, whisk together the brown sugar, white sugar, oil, sour cream, pumpkin puree, sourdough starter, eggs, and vanilla until smooth.
• In a separate bowl, whisk the flour, baking powder, baking soda, salt, and spices.
• Add the dry ingredients to the wet, folding gently until no streak remain. Do not overmix.
• Pour the batter into the prepared pan, smooth the top, and bake 55-65 minutes or until a toothpick inserted in the center comes out clean. If browning to fast, loosely tent with foil at the 40 minute mark.

  Pro Tip: A sourdough quick bread is fully baked once the center reaches 200–205°F (93–96°C) on an instant-read thermometer. This ensures it’s cooked through without drying out.
• Allow the sourdough pumpkin quick bread to rest in the pan for 10-15 minutes before transferring to a cooling rack to cool completely

Make the maple cream cheese frosting

• While the sourdough pumpkin loaf is cooling, make the cream cheese frosting.
• Beat the softened cream cheese and butter until creamy. Gradually add the powdered sugar, beating until fluffy. Mix in the maple syrup and milk for desired consistency.
• Spread frosting evenly over cooled loaf. Chill for at least 30 minutes before slicing for cleaner cuts.
• Store the sourdough pumpkin quick bread in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to 5 days. For longer storage, wrap tightly and freeze for up to 2 months. Thaw at room temperature before serving.