Butter Loaf pan. Combine sugar, milk, and cocoa( or chocolate), cornsyrup, and salt in 2 quart saucepan. Cook over medium heat, stirring constantly, until chocolate melts and sugar is dissolved. Cook, stirring occasioanlly, to 234 F( soft ball stage) Remove from heat, add butter. Cool mix to lukewarm(120 F). Add vanilla, and beat vigorously and continuously 5 to 10 minutes with wooden spoon ( or Mixmaster) Mix will hold its shape when dropped from wooden spoon, shine will not be there. Quickly stir in nut( if desired), spread quickly and evenly in buttered pan. Cool until firm, cut into squares.Makes one pound.