buckle 'buckles' around the fruit leaving a collapsed or are more cake-like than higher batter-to-fruit ratio don't be confused by the sauce and crumb topping as extra fancy blueberry-pineapple buckle filling ½ cup granulated sugar ½ cup milk 1½ tsp baking powder ½ tsp vanilla for sauce cinnamon crumb topping ½ cup granulated sugar ½ cup gold medal all-purpose flour ½ tsp ground cinnamon pineapple sauce tbsp packed brown sugar juice reserved from crushed pineapple until particles resemble fine crumbs sprinkle over blueberry mixture brown and toothpick inserted in center comes out clean water to reserved pineapple juice to cub.com
