Preheat oven to 350 degrees (if using a glass baking dish, reduce heat to 325 degrees).
Prepare the Crust: using a hand held or stand up mixer, cream together butter, shortening and brown sugar. Add salt and flour; mix until well combined. Press the dough into an un-greased 8X8 baking dish.
Bake for 20 minutes at 350 (or 325 if using a glass dish). Remove from oven.
In a separate mixing bowl, prepare the Topping: mix eggs, brown sugar and vanilla together. Add in baking powder and flour and mix until well-combined. Stir in coconut and nuts.
Pour Topping over crust; spread to edges. Return to oven and bake another 20-25 minutes.
Remove from oven and allow to cool at least 30 minutes before serving.
Recipe by My Delicious Blog at https://www.mydeliciousblog.com/yummy-sweetmeats/