This is my favorite caramel corn recipe that I have used for decades. I have tried many other recipes but this one wins out everytime.
1 lb bag brown sugar
1 square butter
1 cup White Karo syrup
1 can Ego brand condensed milk
Cook brown sugar, butter, karo syrup to soft ball stage. Medium boil for 5 minutes then do the cold water test. Should be soft ball stage when you pour a tiny amount in a cup of cold water. Form a ball with fingers, if soft then take off stove. Stir in Condensed milk, bring to boil again and cook for 3 more minutes. Pour over 2 large bowls of popped corn. Stir until all covered.