Prepare the Shortbread Layer:

Preheat the oven to 350°F (175°C). Line a 9x9-inch baking pan with parchment paper, leaving some overhang for easy removal.

In a medium bowl, mix together flour, softened butter, sugar, and salt until a crumbly dough forms.

Press the dough evenly into the prepared baking pan.

Bake for 15–18 minutes, or until the edges are lightly golden. Set aside to cool.

Make the Caramel Layer:

In a saucepan over medium heat, combine the butter, brown sugar, and sweetened condensed milk.

Stir continuously until the mixture begins to boil, then reduce heat to low and simmer for 8–10 minutes, stirring constantly until it thickens and turns a golden caramel color.

Pour the caramel over the cooled shortbread layer, spreading it evenly. Allow it to cool completely.

Add the Chocolate Layer:

Melt the chocolate chips in a heatproof bowl over a saucepan of simmering water, or microwave in 20-second increments, stirring until smooth. (Add vegetable oil or cream if desired for a shinier finish.)

Pour the melted chocolate over the cooled caramel layer, spreading evenly.

Let the chocolate set at room temperature or refrigerate for faster setting.

Slice and Serve:

Once fully set, lift the shortbread out using the parchment paper overhang. Slice into squares or bars and enjoy!