Line an 8-inch square pan with parchment paper, allowing the paper to drape over the edges. Butter the parchment paper lightly.

In a large, heavy-bottomed saucepan, combine granulated sugar, brown sugar, butter, corn syrup, condensed milk, and salt. Stir over medium heat until butter is melted and the mixture is smooth.

Increase heat to medium-high and bring the mixture to a boil, stirring constantly.

Cook, stirring constantly, until the mixture reaches 245°F (firm-ball stage) on a candy thermometer.

Remove the pan from heat and stir in the vanilla extract.

Pour the hot caramel into the prepared pan. Let it cool completely at room temperature.

Once cooled, lift the caramel from the pan using the overhanging parchment paper. Cut into small squares or desired shapes.

Wrap each candy square in wax paper to prevent them from sticking together.