Butter a pan, either 8x8 or larger.

Over medium heat, mix butter, sugar, and corn syrup.

Heat to boiling stirring constantly.

Once Boiling, let it boil for 4 minutes while stirring constantly.

Take off burner for a moment and add the sweetened condensed milk.

Return to medium low heat. Stir constantly until reaches soft-ball stage.

Pour into your buttered pan to cool. Do not scrape the bottom of the pot, as that will result in crunchies.

Let cool. After it has firmed up a bit, cut the caramels before it gets too hard.