In a medium saucepan, combine butter, sugar, corn syrup, and condensed milk. Cook over medium heat, stirring constantly, until mixture comes to a boil.
Reduce heat to low, and cook until mixture reaches a soft-ball stage (235-240 degrees F on a candy thermometer).
Remove from heat, and stir in vanilla extract.
Pour into a greased 9x13 inch pan, and cool completely.
Cut into small pieces, and wrap in waxed paper. Enjoy!
Interesting Facts
Caramels are a type of confectionery which is made by boiling sugar syrup with butter and milk.
Caramels have been around since the 18th century.
The origin of the word caramel is uncertain, but it is thought to come from the Spanish word caramelo, which means "burnt sugar."