Preheat oven to 325°. Place a 9-in. springform pan on a double thickness of heavy-duty foil (about 18 in. square). Wrap foil securely around pan. Line bottom and inside of pan with parchment; set aside., In a small saucepan, cook and stir butter and cream cheese over medium heat until melted. Remove from heat; whisk in cream until smooth. Let cool completely., Sift flour and cornstarch together twice; place in a large bowl. In a small bowl, whisk egg yolks, vanilla, zest and cooled cream cheese mixture until smooth. Add to flour mixture; beat until well blended., In a large bowl with clean beaters, beat egg whites on medium speed until foamy. Gradually add sugar, 1 tablespoon at a time, beating on high after each addition until sugar is dissolved. Continue beating until soft glossy peaks form. Fold a fourth of the whites into batter, then fold in remaining whites. Gently transfer to prepared pan. Place springform pan in a larger baking pan; add 1 in. hot water to larger pan., Bake for 25 minutes. Reduce oven setting to 280°. Bake until top is puffed and springs back when lightly touched and the center appears set, 55-65 minutes longer., Meanwhile, for topping, in a small saucepan, mix sugar, cornstarch and, if desired, cayenne. Whisk in water until smooth. Add cherries; cook and stir over medium heat until thickened and bubbly, about 5 minutes. Remove from heat; whisk in butter. Cool completely., Remove springform pan from water bath. Loosen sides from pan with a knife; remove foil. Remove rim from pan; remove paper. Serve cheesecake warm with confectioners' sugar and cherry topping. Refrigerate leftovers.