Preheat oven to 350°F (180°C). Line baking sheets with parchment paper or silicone baking mats.
Combine the flour, oats, baking soda, cinnamon, nutmeg and salt in a medium sized bowl and set aside.
Cream the butter and sugars together in a large mixer bowl on medium speed until light in color and fluffy.
Add the eggs one at a time and mix until well combined after each.
Add the vanilla extract and mix until well combined.
Add the dry ingredients and mix until the dough is just combined. Do not over mix.
Stir in the apples. Dough will be thick, but sticky.
Create 2 tablespoon sized balls of cookie dough until all the cookie dough has been used.
Bake cookies for 9-12 minutes or until the edges are lightly golden and the centers are just done.
Remove cookies from the oven and allow to cool on baking sheets for 4-5 minutes before transferring to a wire rack to cool completely.
Store cookies in an air tight container.
Cookies are best eaten within 2-3 days.