Preheat the oven to 375°F. Prepare a baking dish (8x11 or 9x9 works well) by spraying with cooking spray, or use a non-stick pan.
Make your flax egg: mix two tablespoons of ground flax seed with 6 tablespoons of water. Set aside and let sit for at least 5 minutes. It will gel up to the consistency of egg whites.
Add dry ingredients to a large mixing bowl: Oats, sugar, and baking powder.
Pour the plant based milk, flax eggs, and vanilla extract into the dry ingredients. Mix well
Stir in the sliced strawberries.
Pour the mixture into the prepared dish. Add additional sliced strawberries on top if you wish. Bake for 1 hour. Check after 45 minutes- the oatmeal is done once the center is set and no longer runny.