01 - Preheat oven to 350°F. Grease an 8×8-inch baking dish with butter or nonstick spray.
02 - In a large mixing bowl, whisk together the rolled oats, cinnamon, nutmeg, baking powder, and salt until evenly distributed.
03 - Add the grated carrots, raisins, and chopped walnuts to the dry mixture. Toss gently to coat everything evenly.
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.
06 - Spread the oatmeal mixture evenly into the prepared baking dish, pressing lightly to create a uniform layer.
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 squares. Serve warm on its own or topped with a dollop of yogurt.