Dissolve coffee crystals in boiling water. Pour over dates and set aside. Peel, core, and shred the apples. In a large mixing bowl, stir together the flour, brown sugar, baking powder, salt, and baking soda. Combine egg, apples, walnuts, melted butter, and coffee-datte mixture. Add to dry ingredients, stirring just till moistened. urn into a greased 9x5x3 loaf pan. Bake at 350 for 60 to 65 minutes or until cake tests done. Cool in pan for 10 minutes. Remove from pan and cool on wire rack.