In a large mixing bowl, whisk together the egg, egg yolk, sour cream, sourdough discard, white sugar, brown sugar, vanilla, pumpkin purée, and oil until smooth.
1 large egg, 1 egg yolk, 2 (30g) Tbsp sour cream, ⅓ (80g) cup sourdough discard, 1 tsp vanilla extract, ¾ (180g) cup pumpkin purée, ⅓ (75g) cup avocado oil , ½ (100g) cup granulated white sugar, ¼ (50g) cup light brown sugar
Sourdough Discard Swap: If you're swapping the discard for additional flour and milk, add the milk to the wet ingredients above and the extra flour to the dry ingredients below.
1/3 (40g) cup all-purpose flour, 3 (40g) Tbsps whole milk
Add the flour, cinnamon, ginger, nutmeg, cardamom, baking soda, baking powder, and salt to the wet ingredients. If you want to use pumpkin pie spice instead of the spices listed, please see the notes under ingredients.
1¾ (220g) cups all-purpose flour, 2 tsp ground cinnamon, ½ tsp ground ginger, ½ tsp ground nutmeg, ⅛ tsp ground cardamom, 1 tsp baking soda, 1 tsp baking powder, ¾ tsp fine sea salt
Mix the dry ingredients into the wet gently until all of the batter is smooth and no streaks remain. Avoid overmixing the batter or the donuts will get tough.
Optional Overnight Fermentation: Cover bowl tightly with plastic wrap and refrigerate for 8–12 hours for added fermentation benefits. If baking the donuts the same day, skip this step.