1. Preheat the oven to 350°F (175°C) and line a 9×13-inch baking pan with parchment paper, leaving an overhang on the sides.

2. In a medium bowl, cream together the softened butter and powdered sugar until light and fluffy.

3. Mix in the vanilla extract, then gradually add the flour and salt, mixing until just combined.

4. Press the dough evenly into the prepared pan using your hands or the bottom of a glass.

5. Bake for 18–20 minutes, or until the edges are lightly golden. Allow to cool completely in the pan.

6. In a microwave-safe bowl, combine the unwrapped caramels and heavy cream.

7. Microwave in 30-second intervals, stirring between each, until the caramel is melted and smooth.

8. Pour the caramel evenly over the cooled shortbread layer and spread it out with a spatula.

9. Let the caramel layer set at room temperature for 30 minutes or chill briefly in the refrigerator.

10. In another microwave-safe bowl, combine the milk chocolate chips and shortening or coconut oil.

11. Microwave in 30-second intervals, stirring between each, until fully melted and smooth.

12. Pour the melted chocolate over the caramel layer and spread evenly with a spatula.

13. Allow the chocolate to set completely at room temperature or refrigerate until firm, then cut into squares or bars.