Berry Nectarine Buckle

Berry Nectarine Buckle

Topping: 1/3 cup all-purpose flour 1/3 cup packed brown sugar 1 tsp. ground cinnamon 3 Tbsp. cold butter Batter: 6 Tbsp. butter, softened 3/4 cup plus 1 Tbsp. sugar, divided 2 eggs 1 1/2 tsp. vanilla extract 2 1/4 cups all-purpose flour 2 1/2 tsp. baking powder 1/2...