Foryoueats: Blueberry Buckle

¾ cup granulated sugar

¼ cup butter softened

1 egg

2 teaspoons lemon zest

1 ½ cups all-purpose flour

2 teaspoons baking powder

½ teaspoon salt

½ cup milk

1 tablespoon all-purpose flour

1 ½ cups fresh blueberries

¼ cup butter + 1 tablespoon, cold

¼ cup brown sugar

¼ cup granulated sugar

⅓ cup all-purpose flour

½ teaspoon cinnamon

Blueberry Buckle