1In small bowl, combine flour, oats and baking soda; set aside. In large mixing bowl, beat 1 cup sugar and butter or margarine until fluffy; mix in egg whites. Stir in dry ingredients. On waxed paper, press dough into 16 x 12 inch rectangle.
2In small bowl, combine pumpkin, remaining 1/2 cup sugar and pumpkin pie spice; mix well. Spread mixture over dough to 1/2 inch of edge. Roll dough, beginning at the narrow end. Sprinkle sesame seeds over roll, pressing gently into dough. Wrap in waxed paper; freeze until firm or overnight.
3Preheat oven to 400 degrees F (200 degrees C).
4Spray cookie sheet with non-stick cooking spray. Cut frozen dough into 1/4 inch slices; place on cookie sheet. Bake 9 - 11 minutes or until golden brown. Remove to wire rack; cool completely.