Preheat oven to 350 degrees.
Line a 8×8 square pan with parchment paper.
In a stand mixer or bowl add the softened butter, shortening and brown sugar and mix well.
Add the flour and on low speed mix. Mixture should be a bit crumbly. If not add 1-2 Tbsp more of the flour.
Press batter evenly in the square pan.
Bake in oven for 10 minutes.
Remove from oven.
In a medium bowl beat the eggs with a hand mixer until they are light and fluffy.
Add the brown sugar, vanilla, coconut, salt, baking powder, gluten free flour and nuts and mix on medium speed.
Spread the mixture evenly on the first layer and place back in the oven and bake for 25-30 minutes, or until it is golden brown.
Remove from oven and sprinkle the butterscotch chips over the bars.
Cool completely.