Preheat oven to 170°C.
In a bowl, mix the peanut butter, maple syrup, apple sauce and vanilla extract till smooth.
Stir in the protein powder, rolled oat and oat flour.
Divide the mixture and add 2/3 of it to the base of a square baking tin. Flatten out evenly.
In a saucepan, heat up the milk. Don't boil it. Stir in the dark chocolate till melted.
Pour the chocolate filling over the base layer and spread out evenly.
Sprinkle the remaining oatmeal mixture evenly over the chocolate layer.
Place into the oven to bake for 10-15mins or until lightly golden. Let it rest for 10 minutes.
Eat it while melted or store it in the fridge.