Preheat the oven to 350˚F.
In a medium bowl, cream together the butter, brown sugar and 2/3 cup granulated sugar until light and fluffy. Beat in the eggs and the vanilla.
In a separate bowl, combine the flour, cornstarch, baking soda, salt and nutmeg. Slowly add the dry ingredients to the wet, mixing until fully incorporated. Fold in the apples.
In a small bowl, combine cinnamon with 1/4 cup of granulated sugar.
Using a medium cookie scoop, form balls with the batter and roll in the cinnamon sugar. Place on a lightly sprayed baking sheet.
Bake for 15 minutes, or until the edges are golden. Transfer to wire racks to cool completely.