First, I focus on the caramel since it needs time to thicken. I combine sweetened condensed milk, butter, brown sugar, and corn syrup in a saucepan over medium heat. Stir continuously until it reaches a rich golden color, then remove from heat and mix in vanilla and salt. Let it cool to room temperature before using.

Next, I preheat the oven to 350°F (175°C) and prepare the pan with parchment. I mix butter, flour, powdered sugar, and salt, then press it firmly into the pan. After pricking it with a fork, I bake it until the edges are lightly golden. Lower the oven to 325°F (163°C) for the next layer.

While the crust cools, I prepare my brownie batter. Once ready, I pour it over the shortbread and smooth it evenly. Bake for about 38-43 minutes until just set, then let it cool completely on a wire rack. For faster cooling, I sometimes place the pan in the freezer for 30 minutes.

I heat heavy cream until it just bubbles, then pour it over chopped dark chocolate. After letting it sit for a minute, I stir until smooth, adding butter and a touch of corn syrup for shine. Let it cool to room temperature so it thickens into a scoopable ganache.

Once the brownies are fully cooled, I spread the caramel evenly on top. Then, I layer the ganache and smooth it carefully. A sprinkle of flaky sea salt makes it pop. Using a warm, sharp knife, I slice them into perfect squares, cleaning the knife after each cut.