Combine sugar, water, and corn syrup in a 3-quart saucepan; cook over low
heat, stirring gently, until sugar dissolves. Wash down crystallized sugar on
sides of pan with a wet pastry brush a few times, as necessary.
Cover and cook over medium heat 2 to 3 minutes. Uncover and cook over medium
heat, without stirring, to hard ball stage (260 degrees F). Remove from heat.
Beat egg whites in a large mixing bowl until stiff peaks form.
Pour hot sugar mixture in a very thin stream over egg whites while beating
constantly at high speed of an electric hand-held mixer.
Add vanilla extract and continue beating just until mixture holds its shape,
about 3 to 4 minutes.
Stir in peanut butter chips and chopped roasted peanuts.