Preheat oven to 175C.
In a bowl mix flour, xanthan gum, baking powder and salt.
In another bowl, cream together butter and sugar.
Add the orange zest and vanilla essence and mix well.
Add milk and vinegar and beat until creamy.
Add in the pistachios and chopped apricots.
Add the flour and make soft and sticky dough.
Divide the dough into two equal parts.
Shape each portion into a log and place them on a greased baking tray.
Bake it for 25-30 minutes or until firm to touch.
Remove from oven and allow it to cool.
Slice the logs with a serrated knife into thin slices.
Preheat oven to 150C.
Place the slices on the baking tray and bake the slices completely dry.
Remove from oven and allow it to cool completely.
They stayed crispy for 2 days. Store in air tight jar and serve it along with a cup of coffee.