For the Shortbread:

1. Preheat oven to 325º F.
2. Line one 8×8 glass or metal pan with parchment paper.
3. Mix flour, baking soda, and salt in a medium sized bowl; set aside.
4. In a separate bowl (or stand mixer) beat the butter, sugar until the mixture is light and fluffy. 
5. Combine half of the flour and all the salt with the wet ingredients and mix until just blended. Then, add the other half of the four and mix until the dough forms a crumbly texture.
6. Press the dough into the prepared pan bringing all the crumbles together to one surface at the bottom of the pan.
7. Bake for 30-35 minutes until soft brown in color.
8. Pull out of the oven and allow to cool to room temperature.

For the Caramel: (Tip: have a candy thermometer on hand if possible)

1. On the stovetop in a medium saucepan melt the butter.
2. Bring saucepan to medium temperature and add the sweetened condensed milk, corn syrup, and salt.
3. Stir the ingredients together gently and constantly to avoid any burning at the bottom of the saucepan.
4. While stirring put in the candy thermometer (if you have one) and bring mixture to about 200F but no more than 225F.
5. The consistency of the caramel will start to come together and thicken. It will turn slightly darker in color. Then add the vanilla and keep stirring.
6. Take caramel off the stovetop and pour over the shortbread in the 8×8 pan.
7. With a rubber spatula spread evenly across the entire pan.

For the Chocolate:

1. In a double boiler add the chocolate of choice. (this can be bars, chips, or anything you like best)
2. Stir chocolate and melt fully.
3. Once fully melted pour over the caramel layer in the 8×8 pan.
4. Spread chocolate evenly. 

Refrigerate for 2-4 hours until the chocolate layer is completely solid. Then pull out of the refrigerator, slice with a sharp knife and enjoy!