INGREDIENTS
1/2 cup
unsalted butter at room temperature
2 tsp
lemon zest
1 cup
sugar
1
egg at room temperature
1 tsp
good-quality vanilla extract
1
and ¾ cup plus ¼ cup all-purpose flour, divided
2 tsp
baking powder
1
teaspoon. kosher salt
2 cups
fresh blueberries
1/2 cup
buttermilk
1 tbsp
turbinado sugar, for sprinkling on top (or use regular sugar)