1. Preheat oven to 350F and line an 8×8 inch baking pan with parchment paper.

2. In a large bowl, cream the butter. Next, add in the sugar salt, and beat until light and fluffy. Add the vanilla and egg yolk then beat until fully combined. Finally, add in the flour and beat until a dough forms.

3. Transfer the dough to your lined pan and press into an even layer. Bake at 350F for about 25 minutes or until the edges are lightly golden.

4. While the shortbread is cooling, make the caramel. In a saucepan combine the butter, brown sugar, salt, vanilla, sweetened condensed milk, and corn syrup.

5. Place over low heat and whisk constantly. The caramel will be done once it reaches 225F. It should start to bubble and darken. Making the caramel should take about 15 minutes.

6. While still hot, pour the caramel onto the shortbread base and smooth it to the edges. Chill for about 20 minutes so the caramel sets.

7. Melt the chocolate chips with the cream either in a double boiler or by microwaving in 30-second increments, stirring in between. Don’t overheat the chocolate or it will burn. Pour the chocolate over the cooled caramel and smooth it into an even layer. Optionally sprinkle with sea salt and chill in the refrigerator for an hour and 30 minutes.