A make-ahead baked oatmeal with berries and flax that gives you a warm, fiber-rich breakfast all week.
Heat the oven to 375F and grease a baking dish.
Mix the oats, flax, baking powder, and cinnamon in a bowl.
Whisk the milk, egg, and maple syrup, then stir into the dry ingredients.
Fold in the berries, pour into the dish, top with walnuts, and bake for 35 minutes until set.