These caramels have the perfect texture—creamy and just a little chewy without threatening to take out your fillings. Be patient when you use the candy thermometer. When you attach it to the side of the pan, make sure the tip isn’t touching the bottom, and watch it carefully. It can seem like the temperature isn’t going up, and then it will suddenly jump. That’s the nature of hot sugar.
2 sticks unsalted butter, plus about 1 tablespoon for the pan
2 cups granulated sugar
1 cup packed light brown sugar
1 cup milk (nonfat or 2 percent)
1 cup heavy cream
1 cup light corn syrup
1 teaspoon vanilla
1/2 teaspoon salt
2 tablespoons bourbon
1–2 teaspoons flaky sea salt
Line a 13 × 9-inch pan with foil and butter the foil. (The easiest way to line a pan with foil without tearing it is to turn the pan over, press the foil over the bottom to shape it, then turn the pan right-side up and drop the foil into it.)
Combine the remaining 2 sticks butter and the sugars, milk, cream, and corn syrup in a 4- to 5-quart saucepan. Place over medium heat, stirring occasionally, until the butter is melted and the sugar is dissolved and the mixture reaches a full boil, 15–20 minutes. (Don’t be tempted to hurry it by cranking up the heat—you may burn it.)
Attach a candy thermometer to the side of the pan, adjusting it so the first couple of inches of the thermometer are immersed but the tip isn’t touching the bottom of the pan. Cook for 25–30 minutes, stirring occasionally and lowering the heat if it starts to darken, until the mixture reaches 244°.
Remove from the heat and immediately stir in the vanilla, 1/2 teaspoon salt, and bourbon. Pour into the prepared pan. Let stand for 5 minutes, then sprinkle with the sea salt.
Let stand for 1–2 hours, until completely cool. Refrigerate until firm, then remove from the pan by lifting out the foil and cut into 2 × 1-inch pieces. Place in an airtight container with wax paper between the layers or wrap each candy in wax paper. Store in the refrigerator.