# What You'll Need:
→ Dough
01 - 3 cups bread flour
02 - 1/2 cup active sourdough starter at 100% hydration
03 - 1 cup whole milk, lukewarm
04 - 1/4 cup unsalted butter, softened
05 - 1/4 cup granulated sugar
06 - 1 large egg
07 - 1 teaspoon fine sea salt
08 - Zest of 1 lemon
→ Blueberry Lemon Swirl
09 - 1 cup fresh or frozen blueberries
10 - 1/4 cup granulated sugar
11 - 2 tablespoons lemon juice
12 - 1 tablespoon cornstarch
→ Optional Glaze
13 - 1/2 cup powdered sugar
14 - 1 to 2 tablespoons lemon juice
# Step-by-step Directions:
01 - In a small saucepan, combine blueberries, sugar, and lemon juice. Cook over medium heat while stirring until the berries burst and release their juice, approximately 5 to 7 minutes. Stir in cornstarch and cook for 1 to 2 minutes until thickened. Transfer to a bowl and cool completely before use.
02 - In a large bowl or stand mixer, combine lukewarm milk, sourdough starter, softened butter, sugar, egg, salt, and lemon zest. Mix until combined. Gradually add flour and knead for 8 to 10 minutes until the dough becomes smooth and elastic.
03 - Place the dough in a lightly greased bowl, cover with a damp cloth, and let rise at room temperature until doubled in size, approximately 4 to 6 hours depending on starter activity.
04 - Turn the dough onto a floured surface and roll into a 9 by 16 inch rectangle. Spread the cooled blueberry swirl evenly over the dough, leaving a 1 inch border on all edges. Roll up tightly from the short end to form a log. Place seam-side down in a greased 9 by 5 inch loaf pan.
05 - Cover the loaf pan and let rise at room temperature for 1 to 2 hours, until the dough is puffy and nearly doubled in volume.
06 - Preheat oven to 350 degrees Fahrenheit. Bake the loaf for 35 to 40 minutes, until golden brown and the loaf sounds hollow when tapped on the bottom.
07 - Once the bread has cooled, mix powdered sugar and lemon juice to achieve a drizzling consistency. Drizzle the glaze over the cooled bread in a decorative pattern.