Lightly spray cookie sheet with no-stick cooking spray or oil lightly.

Beat margarine and 1 ¼ cups sugar until fluffy.

Add yogurt, egg whites, lemon peel and vanilla; mix until well blended.

Gradually add combined remaining ingredients except powdered sugar; mix well.

Cover and refrigerate for 1 to 3 hours.

Heat oven to 375°F.

With lightly floured hands, shape dough into 1-inch balls; place on prepared cookie sheet.

Using bottom of glass dipped in sugar, press into 1/8-inch thick circles.

Bake 10 to 12 minutes or until edges are lightly browned.

Cool 2 minutes on cookie sheet; remove to wire rack.

Sift powdered sugar over warm cookies.

Cool completely.

Store tightly covered.