Here is my contribution. This looks great it is from the book A Century Of Progress In Cooking by Grace Viall Gray Published in 1934

Cut prunes into small pieces. Add sugar and nuts. Beat egg whites until stiff but not dry and fold carefully into prune mixture, blending well....Pour mixture into baked pie shell. Bake in moderately hot oven (375 F.) 30 minutes.... When cold, top with whipped cream to which confectioners sugar and vanilla have been added.