1. Preheat the oven to 350 degree F.
2. Prepare a 9x13 baking pan.
3. In a mixing bowl combine flour, brown sugar and butter.
4. Using a pastry cutter, crumble the butter with the flour until you get a coarse meal texture.
5. Pour the base mixture in the baking pan; press it down for form an even single layer.
6. Bake it for 20 minutes in the preheated oven.
7. In a pot pour condensed milk, butter, corn syrup and brown sugar, over medium heat bring it to a boil and cook for 5 minutes.
8. Remove the crust once done and pour the caramel all over the crust, allow it to cool in the refrigerator just until the caramel sets.
9. In a Pyrex container, melt the aero chocolate bar in the microwave or double boiler.
10. Once done pour the melted chocolate over the set caramel, spread it evenly.
11. And place it in the fridge for the chocolate to set.
12. Once the chocolate is set remove from the refrigerator and cut.
13. Serve the millionaire’s shortbread after a hearty meal.