01 - Preheat oven to 350°F. Grease an 8×8-inch baking dish with butter or nonstick spray.
02 - In a large mixing bowl, stir together the rolled oats, ground cinnamon, ground nutmeg, baking powder, and salt until evenly distributed.
03 - Add the finely grated carrots, raisins, and chopped walnuts to the dry mixture. Toss gently to coat and distribute 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 - Spread the oatmeal mixture evenly into the prepared baking dish, pressing gently to create a uniform layer.
07 - Bake for 35 to 40 minutes, or until the center is set and the top is lightly golden brown. A toothpick inserted in the middle should come out clean.
08 - Let the baked oatmeal cool for 10 minutes before slicing into portions. Serve warm on its own or topped with a dollop of yogurt.