Prunes add fiber to these moist, rich molasses cookies.
Set oven rack in center of the oven; preheat to 350 degrees F. Line 2 baking sheets with parchment paper or spray with cooking spray.
Cover prunes with hot water in a small bowl; let steep for 5 minutes to soften.
Meanwhile, stir together flour, cinnamon, ginger, baking soda and salt in a large bowl. Set aside.
Place the prunes and steeping liquid in a food processor and blend until smooth, about 1 minute. Add 1 cup of the sugar, oil and molasses; blend well. Add to the dry ingredients, along with egg whites, and stir just to combine.
Place a few spoonfuls of sugar in a shallow dish. Form the dough into 1-inch balls. Roll the balls in the sugar and place on the prepared baking sheets, spacing them 2 inches apart. With the palm of your hand, gently flatten balls to a 1/4-inch thickness.
Bake, one sheet at a time, until the bottoms are browned and tops are crackled, 8 to 10 minutes. Transfer cookies to racks and let cool.
Make Ahead Tip: Store in an airtight container for up to 1 week.
(for 2 cookies): 1/2 starch, 1/2 other carbohydrate, 1/2 fat