Mix the raisins with the vanilla in a small bowl and leave to soak for 30-60 minutes.
Preheat oven to 350 degrees and line your baking sheets with parchment paper.
In a medium bowl, sift together flour, baking powder, and nutmeg.
In a large bowl, beat the butter until it is light and fluffy. Then, beat in the sugars until the mixture is light and fluffy. Finally, beat in eggs one at a time until well combined. On a low speed, mix in the dry ingredients until just combined. Stir in the oats, chocolate, and raisins with a wooden spoon.
Place heaping tablespoons of cookie dough on the prepared baking sheets and bake for around 15-18 minutes. Let cool.