Spray a 5 x 9-inch loaf pan with cooking spray. Then, line the pan with waxed paper, folding the corners, and make sure that the waxed paper comes up the sides of the loaf pan at least 2 – 3 inches. Set aside.

Cube the butter and place it in a microwave-safe bowl with the heavy cream. Heat in 30-second increments until the butter has melted, set aside.

In a medium saucepan, combine the water and corn syrup. Add the sugar to the saucepan and stir gently, making sure the sugar is mixed with the liquid.

Bring the mixture to a boil and don’t stir over medium heat and then cover and allow to simmer for 1 minute. This is an important step to make sure that there is no sugar on the sides of the saucepan.

Remove the lid and continue to boil for 5 – 8 minutes. Check the temperature of the syrup using a candy thermometer or instant-read thermometer. You want to cook the mixture until the temperature reaches 320 degrees F. The mixture should have a light amber color around the edges of the pan; do not overcook!

Once the temperature reaches 320 degrees F., carefully pour in about 20% or 1/5th of the melted buttercream mixture.

Stir until it is combined. Repeat with the remaining buttercream mixture until it is all mixed in. Be careful, as the mixture will foam up when you add the butter and cream; you need to do it slowly so it does not boil over.

The temperature will now have dropped. Continue to cook the mixture over medium heat for another 5 – 8 minutes. You want the caramel mixture to reach a temperature between 240 (for soft chewy caramel) and 245 (for harder caramel) degrees F.

Once the caramel reaches the desired temperature, remove it from the heat and immediately pour it into the prepared lined loaf pan.

Sprinkle the sea salt evenly over the top of the caramel while it is still hot. Let cool for about 3 hours at room temperature.

When you go to cut the caramel, if you find it a little too soft, place the pan in the refrigerator for an hour; this will make it easier to cut the caramel into cubes.

Pull the waxed paper out of the loaf pan and place it on a large cutting board.

Using a sharp knife, cut the caramel into cubes about 1/2 to 3/4 of an inch in size.

Cut pieces of waxed paper into 3-inch squares and wrap each piece of caramel in the waxed paper.