Prepare your ingredients and line a 9×13 baking dish with parchment paper, leaving some overhang for easy removal later.
In a stainless steel pan (make sure it is large, the mixture will expand significantly), combine the granulated sugar, light corn syrup, and butter over medium heat. Stir continuously until the sugar has dissolved completely.
Once the sugar has dissolved and the mixture begins to boil, slowly add the evaporated milk – very slowly – stirring constantly
Attach a candy thermometer to the side of the saucepan, making sure it doesn’t touch the bottom. Increase the heat to medium to medium-high stirring constantly.
Allow the mixture to boil until it reaches the soft-ball stage, which is around 238°F (114°C) on the candy thermometer. This usually takes about 25-30 minutes.
Once the mixture reaches the softball stage, remove it from the heat and pour the caramel mixture into the prepared baking dish.
Let it cool for a few minutes, then sprinkle sea salt over the top if desired for that perfect balance of sweet and salty.
Allow the caramels to cool completely at room temperature.
Once they are completely cooled, place them in the freezer for about 20 minutes to make them easier to cut.
Use the parchment paper to lift the caramel block out of the dish.
With a sharp knife, cut the caramel block into individual pieces. You can wrap each caramel in wax paper or parchment paper for storage or enjoy them immediately.