In a large bowl, cream butter or margarine with 1/2 cup of the confectioners sugar until light and fluffy. Mix in 1/2 teaspoon of the lemon extract.Mix in the flour and cornstarch until well mixed. Mixture will appear dry and crumbly. Stir in the orange zest.
Stir in ice water 1 tablespoon at a time until the dough holds together in a ball.Wrap in plastic and refrigerate for at least 2 hours.
Preheat oven to 325 degrees. roll dough into one inch balls.. placeon ungreased cookie sheet and bake eight to ten minutes or until firm and lightly browned. cool slightly and remove to wire racks to cool completely. meanwhile in a small bowl mix remaining sugar with orange juice and the other 1/2 teaspoon lemon extract. When cookies are cool, place waxed paper under rack to catch drips and spoon on glaze. let dry on the rack. makes about 3 doz.(I added the chilling time to the prep time)