Sift together flour, baking powder, sugar and cinnamon. Add butter, shortening, egg yolk, and orange rind. Stir in chocolate chips and nuts.
Shape into 1-inch balls and dip in slightly beaten egg white and roll in cinnamon-sugar mixture.
Place on a greased, non-stick cookie sheet and flatten balls slightly.
Bake at 350 degrees for 15 to 18 minutes. Allow to cool slightly on cookie sheet before carefully removing to a wire rack.