Preheat your oven to 350 degrees.
Grease a 9 inch spring form pan. Set aside.
In a mixing bowl whisk together the flour, cornstarch, baking powder and pumpkin pie spice. Set aside
In the bowl of a stand mixer fitted with the paddle attachment mix together the eggs, brown sugar, vanilla, oil and pumpkin on medium speed until well combined.
Lower the speed to low. Add in the dry ingredients little by little until just absorbed. Do not over mix.
Fold in the apples cut into chunks and pour the batter into the prepared pan.. Top with the sliced apples and sprinkle with granulated sugar.
Bake for 50-55 minutes or until an inserted toothpick comes out clean. Cool before cutting.