Preheat oven to 350 degrees. Grease and flour Rehrucken pan. In a mixing bowl beat together the sugar, egg, orange extract and milk. Mix in the flour and baking powder, mix well. Slowly add the melted butter. Mix well. Pour into prepared pan. Sprinkle with turbinado sugar. Bake for 38 - 40 minutes until golden brown. Remove and place cake on cooling rack, after 10 minutes invert cake out of the pan. Sprinkle with confectioners sugar, if desired prior to serving.