01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking soda, salt, cinnamon, and nutmeg until evenly blended. Set aside.
03 - In a large bowl, beat the softened butter, brown sugar, and granulated sugar together using an electric mixer until light and creamy, about 2 minutes.
04 - Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract until fully incorporated.
05 - Gradually stir the dry ingredient mixture into the wet ingredients until just combined. Avoid overmixing.
06 - Gently fold in the rolled oats, raisins, and diced apple until evenly distributed throughout the dough.
07 - Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart to allow for spreading.
08 - Bake for 11 to 13 minutes, or until the edges are golden and the centers are set but still soft.
09 - Let the cookies cool on the baking sheets for 5 minutes, then transfer to a wire rack to cool completely.