01 - Preheat oven to 350°F. Grease an 8×8-inch baking dish with butter or nonstick spray.
02 - In a large mixing bowl, combine the rolled oats, ground cinnamon, ground nutmeg, baking powder, and salt. Stir until evenly distributed.
03 - Add the finely grated carrots, raisins, and chopped walnuts to the dry mixture. Toss gently to coat the carrots and distribute the add-ins evenly throughout.
04 - In a separate bowl, whisk together the milk, eggs, maple syrup, melted coconut oil, and vanilla extract until smooth and well blended.
05 - Pour the wet mixture into the dry ingredients and stir gently until just combined. Avoid overmixing to maintain a tender texture.
06 - Pour the oatmeal mixture into the prepared baking dish and spread it into an even layer using a spatula.
07 - Bake for 35 to 40 minutes, or until the center is set and the top is lightly golden. A toothpick inserted in the middle should come out clean.
08 - Allow the baked oatmeal to cool for 10 minutes before slicing into portions. Serve warm on its own or topped with a dollop of yogurt.