Preheat oven to 350°F. Line baking sheet with parchment paper. Mix flour, baking powder and salt in medium bowl.
Beat butter, sugar and egg in large bowl with electric mixer on medium speed until a light paste forms. Crumble saffron and mix with water. Add to the paste. Gradually beat in flour mixture until well mixed. Knead dough with floured hands until smooth. Shape into 24 balls. Roll in sesame seed. Place on prepared baking sheet.
Bake 20 minutes or until lightly browned around edges. Remove to wire racks; cool completely.