Melt butter, add the sugars, and stir. Add baking soda, salt, baking powder, vanilla, cinnamon, and beaten eggs. Mix well. Then add the oats, chopped apple and 1 1/2 cups flaked coconut. (Reserve 1/2 cup of flaked coconut for on top.) Add the flour and mix it all throughly.
Grease a 9-inch by 13-inch cake pan. Spoon the dough in and smooth it with a rubber spatula. Sprinkle the 1/2 cup coconut you reserved evenly on top.
Bake at 375 degrees F. for 25 to 30 minutes, or until slightly browned on top.