Preheat the oven to 350°F. Blend together the flour, baking powder, shortening, salt and sugar and set aside one cup of this for use later. In separate bowl, mix the eggs, buttermilk and baking soda together. Then add the remaining of the flour mixture, stirring thoroughly. There will be some small lumps in the batter. To the flour mixture that was set aside add the brown sugar, coconut and cinnamon. Pour the batter mixture into 3 greased and floured 8" cake pans. Sprinkle topping equally on top of batter in all 3 pans. Bake at 350° for 35 minutes.