Preheat oven to 350°. Spray 2 large baking sheets with no-stick cooking spray; set aside.
For Cookies, in medium bowl, combine flour, baking powder and salt; set aside.
In large bowl, with electric mixer, beat I Can't Believe It's Not Butter!® Spread with granulated sugar until light and fluffy, about 4 to 5 minutes. Beat in egg, vanilla and lemon peel. Stir in flour mixture just until blended. On prepared baking sheets, drop dough using tablespoon or small ice cream scoop, 2-inches apart. With hands, flatten slightly.
Bake 9 to 10 minutes or until edges are lightly golden. On wire rack, cool 2 minutes; remove from sheets and cool completely.
Meanwhile, for White Glaze, put confectioners sugar in large bowl. With wire whisk, whisk in boiling water, 1 tablespoon at a time, until mixture is the consistency of a spreadable icing. Remove 1/2 to a small bowl and stir in melted chocolate to make Chocolate Glaze.
Spread 1/2 of each cookie with White Glaze and the other 1/2 with Chocolate Glaze. Let stand until hardened.
