Preheat your oven to 350°F (180°C) and lightly grease a 9x9-inch baking pan with spray oil.
In a large mixing bowl, add the oats, baking powder, cinnamon, salt, and chopped pecans. Toss these dry ingredients together until evenly mixed.
2 ½ cups old-fashioned rolled oats, 1 teaspoon baking powder, 1 ¼ teaspoons cinnamon, ½ teaspoon salt, ½ cup pecans
In a separate bowl, whisk together the eggs, milk, maple syrup, and vanilla extract. Pour the wet mixture over the dry ingredients. Add the melted butter and most of the berries, saving a few to sprinkle on top. Gently fold everything together until well combined.
2 ½ cups berries, 2 eggs, 1 ¾ cups milk or non-dairy milk, ½ cup maple syrup, 2 ½ teaspoons pure vanilla extract, ¼ cup butter
Transfer the mixture to the prepared baking pan, spreading it out evenly. Scatter the reserved berries on top for a colorful touch.
Place the baking dish in the oven and bake uncovered for 40 to 45 minutes, or until the oatmeal is golden brown and set around the edges. If desired, sprinkle a little brown sugar over the top before baking for extra sweetness.
1 tablespoon brown sugar
Once done, remove the baked oatmeal from the oven and let it cool for about 5 minutes. Serve warm, topped with Greek yogurt or whipped cream if you like. Enjoy!
Greek yogurt or whipped cream