1. Preheat your oven to 350.
2. In a large bowl, combine the quick oats, flour, walnuts, both sugars, cinnamon, and nutmeg. Add in the melted butter and stir until all the dry ingredients are wet. Lastly, add in the vanilla and stir.
3. Pour the crumble onto a baking sheet. Press down to form a large crumble. It’s ok that this will be a mix of larger chunks and then portions that are small pieces. Once it bakes you can break up the larger pieces into more of a crumble or keep larger clusters. Bake for 15 minutes.