1
Preheat the oven to 350° F and lightly oil an 8- or 9-inch square baking dish. Mix the flax meal and the water together in a small bowl. Allow them to thicken for a few minutes.
2
In a large mixing bowl, mix together the rolled oats, baking powder, salt, cinnamon, and vanilla powder or vanilla bean (if you're substituting vanilla extract instead, add it to the wet ingredients).
3
Whisk together the prepared flax mixture, the maple syrup, almond milk, and oil. Add the wet ingredients to the oat mixture and stir to combine. Fold in the berries.
4
Turn the mixture out into your baking dish. Top with a few additional berries. Transfer the oatmeal to the oven and bake for 15 minutes. Sprinkle the almonds or pecans and brown sugar over the top and bake for an additional 10 minutes, or until most of the liquid is absorbed and the oats are spongy, but solid. Allow them to cool.
5
You can serve the baked oatmeal either warm or cold. Cut the oatmeal into squares and drizzle with additional non-dairy milk and some fresh jam or maple syrup, if desired. A schmear of almond or cashew butter is also delicious!