Preheat your oven to 350ºF and grease a 10-inch by 7-inch casserole dish with nonstick cooking spray.

Chop the rhubarb into bite-sized pieces and mix with honey in a bowl. Let it sit while you prepare the rest of the ingredients.

Mash the banana in a large bowl using a fork. Then, add the remaining wet ingredients and mix well.

Add the rolled oats, oat flour, baking powder, strawberries, and a pinch of salt to the wet mixture. Stir until well combined.

Incorporate the rhubarb and honey mixture into the batter and mix thoroughly.

Transfer the batter into the prepared casserole dish and spread it evenly with a spatula.

Arrange additional strawberry slices on top for extra sweetness.

Bake in the preheated oven for 33-37 minutes or until the oatmeal bake is firm and golden brown.

Once baked, allow it to cool slightly before serving.