# What You'll Need:
→ Wet Ingredients
01 - 1/2 cup active sourdough starter, unfed or discard
02 - 1/2 cup buttermilk, room temperature
03 - 1/4 cup unsalted butter, melted
04 - 2 large eggs, room temperature
05 - 1 teaspoon vanilla extract
06 - Zest of 1 lemon
07 - 2 tablespoons fresh lemon juice
→ Dry Ingredients
08 - 2 cups all-purpose flour
09 - 3/4 cup granulated sugar
10 - 1 1/2 teaspoons baking powder
11 - 1/2 teaspoon baking soda
12 - 1/2 teaspoon fine sea salt
→ Mix-Ins
13 - 1 cup fresh blueberries, or frozen unthawed
→ Lemon Glaze
14 - 1 cup powdered sugar
15 - 2 to 3 tablespoons fresh lemon juice
16 - 1 teaspoon lemon zest
# Step-by-Step Guide:
01 - Preheat oven to 350°F. Lightly grease two nonstick donut pans with cooking spray or butter.
02 - In a large mixing bowl, whisk together sourdough starter, buttermilk, melted butter, eggs, vanilla extract, lemon zest, and lemon juice until well combined.
03 - In a separate bowl, whisk together flour, granulated sugar, baking powder, baking soda, and salt until evenly distributed.
04 - Add the dry ingredient mixture to the wet mixture and stir gently until just combined. Do not overmix, as this develops gluten and results in tough donuts.
05 - Fold in fresh blueberries, lightly dusting them with flour if desired to help prevent them from sinking to the bottom.
06 - Spoon or pipe the batter into prepared donut pans, filling each cavity approximately 3/4 full.
07 - Bake for 13 to 15 minutes, or until donuts spring back when lightly pressed and a toothpick inserted in the center comes out clean.
08 - Allow donuts to cool in pans for 5 minutes, then carefully turn out onto a wire cooling rack to cool completely.
09 - In a small bowl, whisk powdered sugar, fresh lemon juice, and lemon zest until smooth and pourable.
10 - Dip cooled donuts into the lemon glaze and place on a wire rack to allow excess glaze to drip and set.
