Mash the bananas together with the milk. Add the sugar and eggs. Mix and add the flours, baking powder, oats, and chopped chocolate, and mix well. Place in the Savarin and put inside the casserole. Cook over medium heat for about 1 hour. Check the cooking by inserting a skewer into the pudding. It should come out clean and dry. Once ready, decorate with a light glaze made with confectioners' sugar and lemon juice. Drizzle with chocolate sauce and top with dried banana slices. Serve and enjoy.