In a stand mixer bowl (or large bowl) whisk together the flour, baking powder, baking soda, cinnamon and salt.
5 1/4 cups (665g) all-purpose flour, 1 1/2 tsp baking powder, 1 tsp baking soda, 1/2 tsp salt, 2 tsp ground cinnamon
Add in the egg, pumpkin puree, sourdough discard, milk or buttermilk, vanilla, sour cream, butter and sugar to the dry ingredients.
1/2 cup (100g) granulated white sugar, 1 (50g) large egg, 1/2 cup (120g) sourdough discard (100% hydration), 3/4 cup (200g) pumpkin purée (blotted if watery), scant 3/4 cup (170g) whole milk or buttermilk, 1/3 cup (80g) sour cream, 1 tsp vanilla extract, 1/4 cup (57g) unsalted butter, softened
Knead your dough for roughly 8 minutes on low by mixer or by hand, until everything is well combined. The dough should be well mixed, and will be slightly sticky and wet. If the dough is very sticky and soupy, add 2 Tablespoons (25g) of flour and mix. This dough is rather wet, so be careful here not to add too much flour or the rolls will be dry. See above for how the dough should look when complete.
Cover the bowl with plastic, and transfer to the refrigerator to chill for at least 20 minutes. This makes the rolls easier to shape.
Optional Overnight Fermentation: Cover bowl and refrigerate overnight if you want a longer fermentation if you're gluten sensitive.