Preheat the oven to 350 degrees F. Line a 9X9 baking pan with parchment paper.
Make the shortbread layer. Stir together the flour and powdered sugar and then cut in the butter until it is mixed together to form a crumb mixture. Then press this mixture down into the bottom of the 9X9 pan and bake for 20 minutes. Remove from the oven and cool completely.
Then make the caramel layer. Add the butter to a small sauce pan. Melt over medium high heat. Then stir in the brown sugar. Stir and cook until the sugar is dissolved (stirring constantly). Then whisk in the condensed milk, corn syrup and vanilla extract. Bring this mixture to a boil and cook for 4-5 minutes stirring constantly. Then remove from the heat and stir for a few more minutes until the mixture starts to thicken. Pour the caramel over the shortbread layer and allow for it to cool completely.
Then make the chocolate layer. Put the chocolate chips and heavy whipping cream in a microwave safe pan. Heat in 30 second intervals (stirring after each interval) until the chocolate is completely melted. Then pour the chocolate over the caramel layer (make sure that the caramel layer is firm). Refrigerate the entire pan for 20-30 minutes until the chocolate is fully set.
The cut into bars with a sharp knife and enjoy!
Notes
Store the leftovers in the refrigerator for up to 3-4 days.