• Preheat the oven to 350℉
• Line two muffin tins with 18 cupcake liners.
• In a medium mixing bowl, whisk together the flour, salt, baking powder, and pumpkin pie spice and cinnamon. Set aside
• To a large mixing bowl, mix together the melted butter, oil, pumpkin, vanilla, granulated sugar, brown sugar and sourdough starter. Mix until smooth.
• Slowly, add the flour mixture and continue to stir until mostly smooth with only a few small lumps. If using, add the chocolate chips or nuts and stir until just incorporated.
• Spoon the batter into each cupcake liner until ⅔ of the way full.

  Note: If you choose to add nuts or chocolate chips, this will increase the volume of the batter and you will need a total of 24 cupcake liners.
• Bake for 25-28 minutes, or until a toothpick inserted into the center of one of the muffins comes out clean.
• Allow to cool completely on a wire rack before adding the maple glaze.

For the Maple Glaze

• Melt the butter in a small, microwave-safe bowl for 15 seconds. If butter is not completely melted, stir, and return to microwave for 10 seconds. Continue to stir and microwave at 10-second intervals until the butter is completely melted.
• Add the milk and maple syrup and whisk together until smooth.
• Add the powdered sugar and continue to whisk until the batter is smooth and thick.
• Use a small spoon to evenly divide the glaze over each muffin.