In a small bowl, combine diced apple and lemon juice. Set aside.
In the bowl of a stand mixer, beat the butter and both sugars until creamy, scraping down the sides of the bowl a couple of times, for a total of 3 to 4 minutes. Add egg and beat until combined. Add vanilla and beat again to combine.
In a medium bowl, whisk together the flour, oats, cinnamon, baking powder, baking soda, salt, and nutmeg. Add to the butter and sugar mixture and beat on low speed just until incorporated. With a spatula, fold in the raisins, pecans, and diced apple. Chill dough in refrigerator for 30 minutes.
Preheat oven to 350°. Line two baking sheets with parchment paper and set aside.
Then use a medium scoop to place chilled cookie dough on prepared parchment paper lined baking sheets. Bake for 12 to 13 minutes, until edges are golden. Remove from oven and let cookies cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.
