01 -
In a large mixing bowl, whisk together the flour, salt, baking powder, and both sugars. Gently rub the lemon zest into the mixture to release the oils and break up any brown sugar clumps.
02 -
In a separate bowl, whisk eggs, yogurt, vanilla, and sourdough discard until the mixture becomes thick and pale yellow. Slowly whisk in the cooled melted butter until well combined.
03 -
Pour the wet ingredients into the dry ingredients. Fold gently with a spatula until just combined - a few flour streaks are fine. Reserve about ⅓ of the blueberries for topping, then carefully fold the rest into the batter.
04 -
For the best results, cover and refrigerate the batter for at least 1 hour or overnight. When ready to bake, preheat your oven to 400°F (204°C).
05 -
Line a 12-cup muffin pan with paper liners and lightly grease them. Fill each cup nearly to the top with batter, add 4-5 reserved blueberries on top, and sprinkle with extra granulated sugar.
06 -
Bake for 23-25 minutes until golden brown and a toothpick comes out clean. Let cool in the pan for 5 minutes before transferring to a wire rack.