Preheat oven to 4ooF. Coat nonstick baking sheet with cooking spray.
Stir together yogurt, walnuts, dates, raisins and cinnimon n a smal bowl.
Lightly dust both work surface and biscuits with flour. Roll out on biscuit into 4x6-inch oval. Brush edges with water; spoon 2 Tbs. yogurt mixture in center of bottom half of oval. Fold top half over filling, pressing wet edges together with fingers. Crimp edges closed with a fork. Repeat with remaining biscuits and filling.
Place on prepared baking sheet; bake 15 to 17 minutes, or until puffy and golden.
Meanwhile, blend confectioners' sugar and lemon juice. Remove turnovers from oven, and brush with lemon glaze. Serve hot.