Preheate oven to 350°F. Line a 9x9 inch baking pan with parchment paper and set aside.
Put all shortbread ingredients in a large bowl and using a pastry blender or two knives, work together until you get crumbles that start to turn into a dough-like consistency. Press the mixture firmly into prepared pan and bake for 28-32 minutes, or until it’s just slightly golden brown. Remove from oven and allow to cool slightly.
While cooling, make the caramel layer. Mix together all ingredients expect vanilla in a large saucepan over medium-high heat. Bring to a boil and cook for 6-7 minutes, stirring constantly. Take off the heat and mix in the vanilla and sea salt. Pour the caramel layer over the base layer of shortbread and allow to cool completely. You can place it in the refrigerator or freezer at this point to speed up the cooling process.
Place the chocolate chips in a medium microwave safe bowl and heat on high for 30 seconds. Remove from microwave and stir. Repeat the process until chocolate is melted and smooth. Place the chocolate in a plastic bag or piping bag and cut off a small bit of the tip. Drizzle over the caramel layer and sprinkle generously with sea salt. Immediately Chill before cutting into one inch bars.