# 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
# Steps to Follow:
01 - Preheat oven to 350°F. Lightly grease two nonstick donut pans with butter or cooking spray.
02 - In a large mixing bowl, whisk together sourdough starter, buttermilk, melted butter, eggs, vanilla extract, lemon zest, and fresh lemon juice until thoroughly combined.
03 - In a separate bowl, whisk together all-purpose flour, granulated sugar, baking powder, baking soda, and fine sea salt.
04 - Add dry ingredient mixture to wet ingredients and stir gently until just combined. Avoid overmixing to maintain tender crumb structure.
05 - Gently fold fresh blueberries into batter. Optionally dust blueberries lightly with flour to minimize sinking during baking.
06 - Transfer batter into prepared donut pans using a spoon or piping bag, filling each cavity approximately three-quarters full.
07 - Bake for 13 to 15 minutes until donuts spring back when gently pressed and a toothpick inserted in the center emerges clean.
08 - Allow donuts to rest in pans for 5 minutes, then carefully invert 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 consistency is achieved.
10 - Dip cooled donuts into lemon glaze, allowing excess to drip away, then place on wire rack until glaze sets completely.