1. Combine sugar, water, corn syrup and salt in a 2-qt heavy saucepan.
2. Cook over low heat, stirring
constantly until sugar is dissolved.
3. If sugar crystals form on sides of pan, wipe them off.
4. Cook
to a hard ball stage (252ºF) without stirring.
5. Beat egg whites until stiff.
6. Pour hot syrup slowly
over egg whites, beating constantly.
7. Add vanilla.
8. Continue beating by hand or with electric mixer
on medium speed until mixture begins to lose its gloss and a small amount dropped from a spoon holds soft peaks. (If the candy
gets too stiff for the mixer, complete the beating with a wooden spoon.)
9. Fold in the chocolate pieces quickly
and drop from teaspoon onto buttered waxed paper.
Makes 24 pieces (about 1 lb).