Combine sugar, salt, and corn syrup in a heavy-bottomed saucepan.

Bring to a boil over medium heat, stirring occasionally until the mixture reaches 245°F (firm-ball stage).

Reduce heat to low and gradually add butter and evaporated milk, ensuring the mixture does not stop boiling.

Stir constantly to prevent scorching.

Continue cooking rapidly until the mixture reaches 240°F (soft-ball stage), being careful not to let it burn.

Remove from heat and stir in vanilla extract and chopped pecans.

Pour the hot caramel mixture into a greased baking pan.

Let the caramels cool completely at room temperature before cutting.

Cut into squares using a heavy, sharp knife with a sawing motion.