01 - Preheat the oven to 350°F. Lightly grease a 9×9-inch baking dish with cooking spray or butter.
02 - In a large mixing bowl, combine the rolled oats, ground cinnamon, ground nutmeg, baking powder, and salt. Stir until evenly distributed.
03 - Fold the grated carrots into the dry ingredient mixture, tossing to coat the carrots evenly with the spiced oat blend.
04 - In a separate bowl, whisk together the eggs, milk, melted coconut oil, maple syrup, and vanilla extract until smooth and well blended.
05 - Pour the wet mixture over the dry ingredients and stir until fully combined. Fold in the chopped nuts and raisins, if using.
06 - Pour the mixture into the prepared baking dish and spread it out into an even layer using a spatula.
07 - Bake for 35 minutes, or until the top is golden brown, the center is set, and a knife inserted into the middle comes out mostly clean.
08 - Allow the baked oatmeal to cool for 5 to 10 minutes before slicing. Serve warm on its own or topped with a dollop of yogurt.