Preheat your oven to 350°F (175°C) and lightly grease a 9x9-inch baking dish.
In a large bowl, combine the rolled oats, baking powder, cinnamon, and salt. Mix well.
In another bowl, mix the mashed bananas, milk, honey or maple syrup, and vanilla extract until well combined.
Pour the wet ingredients into the dry ingredients and stir until fully incorporated.
Gently fold in the sliced strawberries and nuts or chocolate chips if using.
Pour the mixture into the prepared baking dish and spread it evenly.
Bake in the preheated oven for 30-35 minutes, or until the top is golden and set.
Allow to cool for about 10 minutes before slicing and serving.