Preheat the oven to 350°F (175°C). Butter the bottom and sides of a 9x13-inch baking pan. Line the base with parchment paper, allowing the edges to slightly overhang for easy removal.

In the bowl of a stand mixer fitted with the paddle attachment, cream together the sugar and softened butter until light and fluffy. Scrape down the bowl as needed. Add the egg and vanilla extract; mix until fully combined. On low speed, gradually incorporate the flour and salt until the mixture resembles coarse, crumbly sand.

Transfer the dough into the prepared pan and press into an even layer. Bake for 20–25 minutes, or until the crust is golden brown. Set aside to cool completely on a wire rack.

Reduce oven temperature to 300°F (150°C). Spread the shredded coconut evenly on a parchment-lined baking sheet. Toast for 15–20 minutes, stirring every 5 minutes, until the coconut turns a golden brown. Allow to cool on the tray.

In a large microwave-safe bowl, combine the unwrapped caramels, milk, and salt. Microwave on high in 30-second intervals for 3–4 minutes total, stirring between intervals, until the mixture is smooth and fully melted.

Fold in the toasted coconut using a spatula until evenly coated.

Spread the caramel-coconut mixture evenly over the cooled shortbread base. Press gently into place using a piece of parchment paper. Allow the bars to cool and set at room temperature or refrigerate briefly if needed.

Once cooled and firm, lift the bars from the pan using the parchment edges. Slice into 30 equal pieces. Line a baking sheet with fresh parchment paper.

Melt the chocolate in a heatproof bowl over a pot of simmering water (double boiler method), stirring until smooth. Dip the base of each bar into the melted chocolate, then place on the prepared tray.

Pour remaining chocolate into a small plastic bag, snip off the corner, and drizzle over the tops of the bars.

Refrigerate the finished bars until the chocolate has set completely. Store in an airtight container once fully cooled.