Step 1

Line the baking dish with parchment paper, leaving enough hanging over two opposite sides to easily lift the cooled caramels out of the pan. Liberally grease the parchment with butter or cooking spray.

Step 2

Combine the white sugar, brown sugar, corn syrup, heavy cream and butter in a 6-quart dutch oven or other heavy bottomed pot. Heat over medium heat and stir constantly until all ingredients are melted and blended together.

Step 3

Affix a candy thermometer to the side of the pot, roughly 1" above the bottom of the pot. Postion the thermometer so that it's submerged below the surface of the caramels throughout the cooking process. Increase the heat to high and bring the sugar mixture to a boil.

Step 4

Once boiling, reduce the heat to medium low and let the sugar mixture simmer with slow, medium-sized bubbles until the candy thermometer reaches 245-250°F. Stir every 10 minutes. It will take 40-45 minutes to reach the correct temperature. NOTE: watch the thermometer carefully after it reaches 230°F, as the temperature increases pretty quickly after that point.

Step 5

Once the mixture hits 245-250°F, immediately remove from heat and pour in 1/2 tsp fine sea salt and the vanilla. The mixture will vigorously bubble (this is the alcohol in the vanilla boiling off). Stir in the vanilla until evenly incorporated, then pour the caramel into the prepared baking dish. Use oven mitts to protect your hands and wrists from any splatter (it's extremely hot!). Allow the caramel to cool at room temperature for 15-20 minutes and then sprinkle half the maldon salt over the caramels.

Step 6

Allow the caramels to cool at room temperature or in the fridge until set - at least 2 hours. Once cooled, sprinkle the remaining salt over the caramels. Lift up the caramels by the parchment paper flaps and transfer to a cutting board. Cut the caramels into 1" x 2/3" rectangles with a sharp, non-serrated blade or a bench scraper. Wrap the caramels in 4" x 5" squares of wax paper.

Step 7

The caramels are good for 2-3 weeks if stored in an airtight container. I gift these in 1-lb gift boxes in 1.5 dozen increments.