For best results, use very cold butter. This will help create a flaky and tender crumb topping. If you don't have self-rising flour, you can make your own by combining 1 1/2 cups all-purpose flour with 2 1/4 teaspoons baking powder and 3/4 teaspoon salt. Feel free to experiment with other fruit compotes, such as raspberry or blueberry. Store leftover bars in an airtight container at room temperature for up to 3 days or in the refrigerator for up to 1 week.