1
: Line 8-inch (2 L) square baking pan with waxed paper; set aside
2
: Combine sugar, evaporated milk, butter and salt in medium saucepan; bring to rolling boil over medium heat, stirring constantly. Boil 4 to 5 minutes or until mixture starts to thicken. Remove from heat. Stir in marshmallows, chocolate chips, vanilla and nuts (if desired) until marshmallows and chocolate melt and blend.
3
: Pour into prepared pan. Chill until set 4 hours or over night. Cut into 1-inch (2.5 cm) squares. Store in refrigerator in sealed container.