Millionaire Shortbread (Caramel Squares)

Ingredients

• 2 1/4 cups All-purpose flour
• 2/3 cup Granulated sugar
• 2 sticks (8 oz) + 6 tbsp (for caramel) sticks + tbsp Unsalted butter
• 1 teaspoon Vanilla extract
• 1/2 teaspoon Kosher salt
• 1 cup Demarara sugar
• 1/2 cup Light corn syrup
• 3/4 cup Heavy cream
• 14 oz can Sweetened condensed milk
• 1 whole Vanilla bean
• 7 oz Bittersweet chocolate (about 60-68%)
• to taste Flaky salt
• 1 sheet Parchment paper