Start by preheating your oven to 350℉ (175℃). While it heats, grab a 2-quart or 8-inch square baking dish and grease it with a little melted coconut oil or unsalted butter. This step is crucial as it prevents the oatmeal from sticking.
In a large mixing bowl, combine 1½ cups milk, ⅓ cup maple syrup, 1 large egg, 1 teaspoon vanilla extract, 1 teaspoon pumpkin pie spice, 1 teaspoon ground cinnamon, ¼ teaspoon kosher salt, 1 cup 100% pumpkin puree, and 1 teaspoon baking powder. Whisk these ingredients together until they’re smooth and well combined, creating a lovely mixture that smells divine.
Next, stir in 2 tablespoons melted coconut oil or butter. This addition gives richness and enhances the overall flavor, so don’t skip it. Then fold in 2 cups uncooked rolled oats, mixing gently until everything is just combined. If you'd like to, add in any optional ingredients like chopped nuts or chocolate chips at this stage.
Pour the oatmeal mixture into the prepared baking dish, spreading it out evenly with a spatula. At this point, if you want to prepare ahead, you can cover the dish with plastic wrap and refrigerate it for up to 24 hours. Otherwise, let it sit at room temperature while your oven finishes preheating.
Once your oven is ready, remove the baking dish from the refrigerator if you’ve prepped ahead and allow it to come to room temperature. This helps ensure even baking. Bake uncovered for 25 to 32 minutes, until the oats are set and the top is lightly golden. You'll know it’s done when the edges pull slightly away from the sides of the pan.
When your Pumpkin Baked Oatmeal is out of the oven, let it cool for a few minutes before slicing. Serve warm, drizzled with additional maple syrup and garnished with a sprinkle of nuts if desired. I love enjoying it with a hot cup of coffee or tea!