Preheat the oven to 425 degrees F and line a muffin tin with muffin liners. Set aside. In a large bowl, whisk together the flour, baking powder, baking soda, cinnamon, pumpkin pie spice and salt. Set to the side.
310 grams all-purpose flour, 8 grams baking powder, 10 grams baking soda, 6 grams salt, 5 grams ground cinnamon, 4 grams pumpkin pie spice
In a medium bowl add the sourdough discard, sugars, eggs, pumpkin puree, and melted butter. Whisk until the ingredients are combined and smooth.
120 grams sourdough discard, room temperature, 100 grams granulated sugar, 150 grams eggs, room temperature, 425 grams pure pumpkin puree, canned, 113 grams unsalted butter, melted, 110 grams light brown sugar
Pour the wet ingredients into the dry ingredients and mix until the dry ingredients are just combined. Be careful not to overmix the batter, otherwise this will lead to a dense muffin. Let the batter rest for 15 minutes. This short rest helps to hydrate the flour, making the muffins extra fluffy!
While the batter is resting, prepare the cream cheese filling and crumble topping.