Petit Fours Icing

1/2 cup hot water
3 cups granulated sugar
1/4 teaspoon cream of tartar
1 teaspoon vanilla extract
2 1/2 cups confectioners' sugar, sifted

Put hot water, sugar and cream of tartar into a saucepan. Cover and bring to a boil. Uncover and cook to 226 degrees F on a candy thermometer. Cool at room temperature to 110 degrees F. Add remaining ingredients. Tint as desired. Spoon over cakes on racks.