Preheat your oven to 350°F (175°C) and line an 8×8-inch square pan with parchment paper.

Cream together 1 cup unsalted butter and 0.5 cup granulated sugar until light and fluffy, about 3–4 minutes.

Add in 2 cups all-purpose flour, 0.25 teaspoon salt, and 1 teaspoon vanilla extract. Mix on low speed until a soft dough forms.

Press the dough evenly into the bottom of the prepared pan and prick the surface with a fork to prevent bubbling.

Bake for 20–22 minutes, or until the edges turn light golden brown. Let cool completely on a wire rack.

In a medium saucepan, combine 1 cup sweetened condensed milk, 0.5 cup light brown sugar, 0.5 cup unsalted butter, 2 tablespoons light corn syrup, and 0.25 teaspoon salt. Stir over medium heat for 8–10 minutes until thickened.

Remove from heat and stir in 0.5 teaspoon vanilla extract. Pour the caramel over the cooled shortbread layer.

Chill the pan in the fridge for at least 1 hour to set the caramel layer properly.

Melt 1 cup chocolate chips with 2 tablespoons heavy cream. Stir until smooth and glossy.

Spread the chocolate mixture over the chilled caramel layer and return to the fridge for another hour to set.

Remove from the pan using the parchment overhang and slice into 16 squares with a hot knife for clean cuts.

If desired, garnish with flaky sea salt or dust with powdered sugar before serving.