Preheat oven to 350º F. Mix together ingredients for shortbread crust recipe and press into a 9x13 rimmed baking pan. Bake 12-15 minutes, until golden brown. Remove from the oven. Reduce oven temperature to 325º F.
While crust is baking, beat egg whites on high speed until fluffy. Reduce speed and stir in coconut, condensed milk vanilla and pinch of salt. Spread onto baked crust and bake for 12 minutes or until set and coconut begins to turn light brown. Remove from oven and drizzle caramel and chocolate sauces over, if using.