Directions
Preheat the oven to 350 degrees F (177degrees C). Spray a 9x13-inch (23x33-cm) baking dish with pan spray. Cut a piece of waxed paper to fit the bottom of the pan, lay it in, and spray over the whole bottom.
Soak the prunes in hot water for 15 minutes to soften. Puree in a food processor or blender. Combine pureed prunes, cocoa, vanilla, and oil in a medium bowl and mix well. Add the buttermilk and whisk until the mixture is smooth, with no lumps of cocoa. Whisk in the egg whites until light.
Mix the sugar, flour, salt, and soda in a large mixing bowl. Fold in the chocolate mixture and then stir in the rice cereal. Pour into the prepared pan and bake for 25 minutes or until a toothpick inserted in the middle comes out clean. Cool and cut into 24 pieces.