Puree whole almonds in blender. Beat 3 egg whites until foamy and add pureed almonds, sugar, flour, and vanilla. Mix well until mixture becomes pliable. It is stiff, bean in another egg white. With your fingers take small pieces of the mixture, roll in chopped almonds and form into "fingers". Arrange them on a lightly greased baking sheet and bake in a preheated 325-degree oven until light golden, about 20 minutes. Do not remove from baking sheet until cooled.