In a bowl combine all the dry ingredients and diced butter. Rub mixture briskly between finger tips until it forms small moist clumps in a loose sandy mixture. Refrigerate while preparing the apples.
Cut a small layer off the bottom of each apple to create a flat, stable bottom surface. With a small paring knife, cut a cylindrical cone out of the top of the apple, moving about 1-inch outside of the core, similar to removing the top of a pumpkin when carving a Jack O'Lantern. Remove the top and discard. With a melon baller or a teaspoon, remove the remaining core and seeds taking care not to puncture the base of the apple.
Bake in oven at 350 degrees on the top or middle rack for 40 minutes or until filling is golden brown and the tip of a paring knife can be inserted into the side of the apple with little or no resistance. Let apples stand for 10 minutes before serving.