Make the Shortbread Base:

1. Preheat the Oven:
   • Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang for easy removal.
2. Prepare the Dough:
   • In a mixing bowl, cream the butter and sugar together until light and fluffy. Gradually mix in the flour and salt until a crumbly dough forms.
3. Bake the Base:
   • Press the dough evenly into the prepared baking pan. Prick the surface with a fork to prevent bubbling. Bake for 20–25 minutes, or until golden and firm. Let it cool completely.

Make the Caramel Layer:
4. Cook the Caramel:

• In a medium saucepan over medium heat, melt the butter, brown sugar, golden syrup, and sweetened condensed milk, stirring constantly. Once combined, bring to a gentle boil and cook for 5–7 minutes, stirring constantly, until thickened and golden.

5. Pour the Caramel:
   • Pour the caramel evenly over the cooled shortbread base. Use a spatula to smooth the surface. Let it cool and set completely at room temperature or in the refrigerator.

Make the Chocolate Topping:
6. Melt the Chocolate:

• In a microwave-safe bowl, melt the chocolate chips and coconut oil (if using) in 30-second intervals, stirring between each, until smooth.

7. Top the Caramel Layer:
   • Pour the melted chocolate over the caramel layer and spread evenly. Let it set at room temperature or in the refrigerator until firm.

Slice and Serve:
8. Cut into Bars:

• Once the layers are fully set, lift the shortbread out of the pan using the parchment overhang. Slice into squares or rectangles using a sharp knife. For clean cuts, warm the knife slightly between slices.

9. Serve:
   • Enjoy as a rich dessert or snack. Store leftovers in an airtight container at room temperature or in the refrigerator for up to 1 week.