Add flour, baking soda, baking powder, and salt to a large bowl and combine well.
Add sourdough starter, maple syrup, eggs, yogurt, and melted and cooled unsalted butter to a medium bowl and combine well.
Add wet ingredients to bowl of flour mixture and combine well until a thick batter forms.
Cover bowl with damp cloth and let ferment at room temperature for 5-6 hours.
Preheat oven to 350 degrees Fahrenheit.
Prepare a loaf pan with parchment paper.
Remove cloth from bowl and fold blueberries, lemon juice, and lemon zest into batter.
Pour/scoop batter into prepared pan and spread into an even layer. Add brown sugar or turbinado sugar on top now, if using
Place loaf pan in the center rack of the oven.
Bake for about 1 hour, or until the top is slightly golden brown and a toothpick comes out clean when inserted into the center.
Remove from oven and carefully transfer loaf to a wire rack. Let bread cool for at least 30 minutes before serving.
This bread can be enjoyed warm, room temperature, or chilled.
Add glaze on top of the loaf once cooled, if using glaze instead of a sugar topping.
Enjoy!