Meltaway Cookies. 1 C. butter ¾ C. cornstarch ¾ C. powdered sugar 1 C. flour 1 recipe Cream Cheese Frosting (see below) In a medium bowl, cream butter until fluffy. Add cornstarch & sugar and blend well. Beat in flour until thoroughly mixed. Drop by small teaspoons onto baking sheet & flatten out with the bottom of a glass.