Preheat oven to 350 degrees F. Grease 8x8 or 7x10 inch baking dish and set aside.
Place banana in a large bowl and mash with a fork until it is the texture of a puree. Mix in vanilla extract, melted butter, and maple syrup, stirring until homogenous.
Next add oats, flour, and baking powder, mixing thoroughly.
Pour in milk and crack both eggs over the mixture, stirring again until all are combined.
Pour in raspberries and chocolate chips. Mix until they are evenly distributed throughout the batter.
Pour into your greased dish and bake for 30 minutes.
Allow to cool before slicing and serving.