Preheat the oven: Preheat the oven to 350°F (175°C). Grease an 8×8-inch baking dish or line it with parchment paper for easy removal.
- Prepare the dry ingredients: In a large mixing bowl, combine the oats, baking powder, salt, cinnamon, nutmeg, and ginger (if using). Stir until well combined.
- Prepare the wet ingredients: In another bowl, whisk together the milk, eggs, maple syrup (or honey), and vanilla extract until smooth.
- Combine the wet and dry ingredients: Pour the wet mixture into the dry ingredients and stir to combine. Add the grated carrots, raisins, nuts, and shredded coconut (if using), and mix until everything is evenly distributed.
- Assemble the oatmeal: Pour the oatmeal mixture into the prepared baking dish and spread it out evenly.
- Bake: Bake for 30-35 minutes, or until the oatmeal is set and golden brown on top. You can check for doneness by inserting a toothpick in the center—it should come out clean.
- Cool and serve: Allow the baked oatmeal to cool for a few minutes before slicing into squares. Serve warm with a dollop of Greek yogurt or a drizzle of extra maple syrup if desired.