Preheat oven to 350 degrees. Prepare baking sheet with cooking spray. In a mixing bowl, combine pumpkin and egg whites. In another mixing bowl, combine sugar, flour, baking soda, cinnamon, nutmeg, cloves, oats, and raisins. Mix wet ingredients with dry ingredients just until moistened. Drop by tablespoonfuls onto prepared baking sheet, 5 cm apart. Bake for 15 minutes, or until they seem firm.