Preheat the oven to 350°F (175°C). Grease a baking dish.

In a mixing bowl, combine the dry ingredients: rolled oats, baking powder, cinnamon, nutmeg, salt, and brown sugar.

In another bowl, whisk together the wet ingredients: pumpkin puree, milk, eggs, and vanilla extract.

Pour the wet mixture into the dry ingredients and stir until well combined.

If desired, fold in optional toppings like nuts or dried fruit.

Transfer the mixture to the prepared baking dish and spread it evenly.

Bake in the preheated oven for 30-35 minutes, or until the top is golden and a toothpick comes out clean.

Let it cool for a few minutes before serving.