Step 1 – Make the Dough: In a large mixing bowl, combine the active sourdough starter, warm water, and sugar. Stir to dissolve. Add bread flour, salt, and lemon zest. Mix until a shaggy dough forms. Knead on a lightly floured surface for 8–10 minutes, or until smooth and elastic. Place in a lightly oiled bowl, cover, and let it rise at room temperature for 4–6 hours, or until doubled in size.

Step 2 – Prepare the Filling: In a medium bowl, beat the cream cheese and powdered sugar until smooth. Gently fold in the blueberries and lemon juice.

Step 3 – Shape the Bread: Once the dough has risen, punch it down gently. Roll it out into a rectangle about ½ inch thick. Spread the cream cheese filling evenly, leaving a 1-inch border around the edges. Roll the dough up tightly from the long side, just like making cinnamon rolls. Twist the rolled dough into a spiral or braid, then place it into a greased loaf pan or shape it free-form on parchment paper.

Step 4 – Second Rise: Cover and let the dough rise again for 1–2 hours, until puffy but not over-proofed.

Step 5 – Bake: Preheat oven to 375°F (190°C). Bake for 35–40 minutes, or until golden brown and the internal temperature reaches 190°F (88°C). If the top browns too quickly, cover loosely with foil for the last 10 minutes.

Step 6 – Cool & Glaze: Let the bread cool for at least 45 minutes before slicing. For the glaze, whisk powdered sugar and lemon juice until smooth, then drizzle over the cooled loaf.