Preheat oven to 325.
Line 8x8 pan with parchment and butter or spray parchment, set aside.
Combine butter, flour, salt and sugar in a stand mixer with dough hook attachment. Work until a ball of dough forms (be patient, it will happen!).
Press shortbread dough into prepared pan. Bake 45 minutes until sides are slightly golden.
Remove from oven and allow to cool until you can easily touch the pan and shortbread.
Meanwhile, combine coconut and caramel. Spread evenly over the cooled shortbread.
Melt chocolate chips; pour over shortbread/coconut caramel evenly. Top with flaky salt if using.
Chill an hour or until chocolate is hard. Slice into desired size. Keep in an airtight container in the refrigerator. Enjoy chilled!