Preheat the oven to 180°C (355°F).
Lightly grease an 8 × 10-inch (20 × 25 cm) baking dish with coconut oil.
Slice each strawberry into 3–4 pieces.
In a large mixing bowl, combine the rolled oats, chia seeds, and baking powder.
Pour in the oat milk, maple syrup, vanilla extract, and lemon zest. Stir until everything is well combined.
Fold in three-quarters of the strawberries.
Pour the mixture into the prepared baking dish.
Scatter the remaining strawberries evenly over the top.
Bake the Baked Strawberry Oatmeal for about 35 minutes, or until set and lightly golden.
Allow it to cool for 10 minutes before serving.
Enjoy with yogurt, extra milk, or a drizzle of maple syrup if desired.