This is an old recipe from the back of a 60s or 70s DOMINO POWDERED SUGAR box similar to the one pictured below.
1 lb Donino Confectioners 10-X Powdered Sugar
1/3 cup butter or margarine, softened
1/4 tsp salt
1 tsp vanilla extract
1/3 cup light corn syrup
Mix all ingredients together until well blended. Put on board and knead until perfectly smooth and satiny. Tint with food color if desired. Shape and use as desired in making any of the following candies:
NUT SQUARES OR DIAMONDS: Knead 1/2 cup toasted chopped almonds, filberts, hickory nuts, butternuts, pecans, or walnuts into fondant. Substitute almond extract for the vanilla extract. Roll out fondant 1/3-inch thick. Cut into small squares or diamonds. Let dry and store pieces in airtight container.
MINTS: Omit vanilla and add a few drops oil or extract of peppermint or wintergreen. Tint green or pink. Shape into 3/4 inch balls and flatten into patties with a fork. Let dry and store in airtight container.