Preheat oven to 350°F Lightly grease a 9×13-inch baking pan, or line with parchment paper.
In a large bowl, cream together sugar and butter, until fluffy. Beat in egg and vanilla extract. Working at a low speed, gradually beat in flour and salt until mixture is crumbly, like wet sand. The dough does not need to come together. Pour crumbly dough into prepapred pan and press into an even layer.
Bake for 20-25 minutes, until base is set and edges are lightly browned. Cool completely on a wire rack before topping.
Preheat oven to 300. Spread coconut evenly on a parchment-lined baking sheet (preferably one with sides) and toast 20 minutes, stirring every 5 minutes, until coconut is golden. Cool on baking sheet, stirring occasionally. Set aside.
Unwrap the caramels and place in a large microwave-safe bowl with milk and salt. Cook on high for 3-4 minutes, stopping to stir a few times to help the caramel melt. When smooth, fold in toasted coconut with a spatula.
Put dollops of the topping all over the shortbread base. Using the spatula, spread topping into an even layer. Let topping set until cooled.
When cooled, cut into 30 bars with a large knife or a pizza cutter (it’s easy to get it through the topping).
Once bars are cut, melt chocolate in a small bowl. Heat on high in the microwave in 45 second intervals, stirring thoroughly to prevent scorching. Dip the base of each bar into the chocolate and place on a clean piece of parchment or wax paper. Transfer all remaining chocolate (or melt a bit of additional chocolate, if necessary) into a piping bag or a ziploc bag with the corner snipped off and drizzle bars with chocolate to finish.
Let chocolate set completely before storing in an airtight container.
Makes 30 bar cookies.
Note: You can simply drizzle chocolate on top of the bars before slicing them up if you’re looking for yet an easier way to finish these off. You won’t need quite as much chocolate as noted above, and you won’t quite get the Samoas look, but the results will still be tasty.