From the Smitten Kitchen Cookbook.

4 cups (945 ml) apple cider

1/2 tsp ground cinnamon

2 tsp flaky sea salt

8 Tbsp (115 grams or 1 stick) unsalted butter, cut into chunks

1 cup (200 grams) granulated sugar

1/2 cup (110 grams) packed light brown sugar

1/3 cup (80 ml) heavy cream

Neutral oil for the knife

• Boil the apple cider in a 3- to 4- quart saucepan over high heat until it is reduced to a dark, thick syrup, between 1/3 and 1/2 cup in volume.
• This takes about 35 to 40 minutes on my stove.
• Stir occasionally.
• Meanwhile, get your other ingredients in order, because you won’t have time to spare once the candy is cooking.
• Line the bottom and sides of an 8-inch straight-sided square metal baking pan with 2 long sheets of criss-crossed parchment. Set it aside.
• Stir the cinnamon and flaky salt together in a small dish.
• One you are finished reducing the apple cider, remove it from the heat and stir in the butter, sugars, and heavy cream.
• Return the pot to medium-high heat with a candy thermometer attached to the side, and let it boil until the thermometer reads 252 degrees, only about 5 minutes. Keep a close eye on it.
• If you don’t have a candy or deep-fry thermometer? Have a bowl of very cold water ready, and cook the caramel until a tiny spoonful dropped into the water becomes firm, chewy, and able to be plied into a ball.
• Immediately remove caramel from heat, add the cinnamon-salt mixture, and give the caramel several stirs to distribute it evenly.
• Pour caramel into the prepared pan.
• Let it sit until cool and firm – about 2 hours, though it goes faster in the fridge.
• Once caramel is firm, use your parchment paper sling to transfer the block to a cutting board.
• Use a well-oiled knife, oiling it after each cut (trust me!), to cut the caramel into 1-by-1 inch squares.
• Wrap each one in a 4-inch square of waxed paper, twisting the sides to close.
• Caramels will be somewhat on the soft side at room temperature, and chewy / firm from the fridge.
• Caramels keep in an airtight container at room temperature for two weeks – but really, good luck with that!