In a large bowl, cream together the butter, copha, white sugar and brown sugar until smooth. Beat in the eggs one at a time, then stir in the vanilla. Combine the plain flour, wholemeal flour, oats, baking powder and bicarb soda; blend into the creamed mixture to form a dough. Fold in the white chocolate chips and pistachios. Drop dough by teaspoonfuls onto ungreased baking trays.
Bake for 8 to 10 minutes in the preheated oven. Allow biscuits to cool on baking tray for 5 minutes before removing to a wire rack to cool completely.