• Preheat your oven to 350F and line a 13x9 baking pan with parchment paper, making sure to cover both the bottom and up all four sides. I like to tack it down with a little spray of olive oil to present it shifting around the pan.

Shortcrust Layer

• In a medium bowl, mix together flour and salt with a whisk, and set aside.
• Using a stand mixer, or an electric mixer coupled with a large bowl, cream the butter and sugars for the shortbread, until light and fluffy.
• Add egg and vanilla extract and combine well. Scrape down the sides of your bowl to make sure everything is evenly incorporated.
• Add the flour/salt mixture slowly, about a third at a time, scraping down the bowl after each addition.
• The dough is complete when mixed, but slightly crumbly.
• Drop dough into prepared 9 x 13 pan, and cover with another piece of parchment. Using the flat bottom of a heavy glass, press dough evenly across the bottom of the pan and into the corners.
• Peel off top layer of parchment.
• Bake at 350 for 20-25 minutes. The edges should start to turn golden, but because of the flour, the majority of the shortbread will still be pretty pale.
• Cool and prepare the caramel for the next layer.

Caramel Layer

• Combine sweetened condensed milk, butter, brown sugar, and corn syrup in a medium-sized saucepan over medium heat. My stove dial runs from 2-9, I heat on 6.
• Whisk constantly until butter is melted, ingredients are well-combined, and mixture begins to boil. This step will take awhile, it will feel like forever, but do not increase the heat.
• Once boiling, reduce heat to a simmer ( I drop the heat on my stove to about 3.5), and continue stirring until mixture darkens to a caramel color, and starts to become fragrant.
• Continue stirring until the caramel thickens and pulls away from the sides of the pot.
• Remove from heat and immediately stir in the vanilla extract and salt.
• Pour evenly over the cooled shortbread, using a knife or offset spatula to create an even layer.
• Cool in the refrigerator for at least one hour.
• Prepare the chocolate layer once the caramel is cool.

Chocolate Layer

• Combine chocolate chips and cream in a saucepan over medium heat, on my stove a 6.  
• Mix until chocolate is melted and well combined with the cream.
• Remove from heat, add vanilla, and stir well.
• Cool one minute.
• Pour over top of the chilled caramel layer. Smoothing if necessary.
• Top with flaked salt and coarsely chopped hazelnuts.
• Refrigerate for thirty minutes.
• Cut the bars into 24 portions and serve.