When the seed cracks, it enhances the flavor of the fruit preserves, adding a nuttiness. While traditionally, crack seed has been ground up to be used as a snack or dessert topping, today, crack seed refers to any sweet and sour dry preserved fruit, and the variety is dizzying, from fig, ginger, guava, and kumquat, to lemon, mango, pineapple, starfruit, and more.