Buttermilk Blueberry Breakfast Bake

Name: Buttermilk Blueberry Breakfast Bake
Total time: 1 h
Yield: 12-16
Ingredients: 2 cups Blueberries, fresh; 1 Lemon; 1 Egg, large; 2 cups All-purpose flour; 2 tsp Baking powder; 1 tsp Kosher salt; 1 cup Sugar; 1 tsp Vanilla extract; 1/2 cup Butter, unsalted; 1/2 cup Buttermilk