Preheat the oven to 350°F. Lightly grease an 8" square or 9" round pan., To make the topping: Drizzle the 1 tablespoon butter and boiled cider into the bottom of the pan., Mix the cranberries and diced apples, and spread into the pan. Sprinkle with the sugar., To make the cake: Stir together the cake ingredients, mixing until smooth., Spread the batter over the fruit in the pan., Bake the cake for 35 to 40 minutes, until the center feels firm when pressed, and a toothpick inserted into the middle comes out clean., Remove the cake from the oven, and invert it over a heatproof serving plate. Wait a few seconds, then carefully lift off the pan. Scrape any stuck-on fruit in the pan back onto the cake., Serve warm or at room temperature. Whipped cream is a suitable accompaniment.