Preheat the oven to 350°F. Line a baking sheet with parchment paper and set aside.
In a medium bowl, mix together the oats, flour, baking soda and cinnamon. Set aside.
In a seperate bowl, cream together the butter and sugar until light and fluffy. Mix in the egg, milk and vanilla until fully combined.
Slowly mix in the dry ingredients into the wet ingredients until fully incorporated. Fold in the raisins and apples.
Using a cookie scoop, scoop the cookie dough onto the prepared baking sheets and bake in the preheated oven for 15-20 minutes, or until lightly browned. Allow to cool for around 2 minutes on the baking sheets before transferring to wire racks to cool completely.