Preheat oven to 375F. Spray 9×13 baking dish with cooking spray and set aside.
In large bowl, combine oats, baking powder, cinnamon, nutmeg, and salt. Stir well to combine.
In medium bowl, whisk together milk, vanilla, honey, eggs, and oil. Pour wet ingredients into dry ingredients and stir until combined. Fold in zucchini.
Pour into prepared baking dish. Bake in preheated oven for 30-35 minutes, until baked through and golden brown on top. Let cool, then scoop into bowls. You can serve as is or pour a little bit of milk or cream on top. Keep covered in refrigerator, for up to a week.