Step #1
In a heavy bottomed saucepan over med-heat/flame, brown sugar, mix the butter, sweetened condensed milk, corn syrup & salt.
Step #2 Bring to a boil, stirring constantly.
Step #3 Heat to between 234 & 240 degrees F (112 to 116 degrees C), or until a small amount of syrup dropped into cold water forms a soft ball that flattens when removed from the water & placed on a flat surface.
Step #4 Cook for 2 mins at that temperature.
Step #5 Meanwhile, butter a 9x13 inch baking pan.
Step #6 When the caramel is ready, pour this into the buttered pan.
Step #7 Allow to cool completely at about room temp.
Step #8 Remove from the pan & cut into squares using scissors.
Step #9 Wrap individual pieces in waxed paper or cellophane.