In a large bowl with an electric beater, beat the ricotta and sugar until combined well. Add the heavy cream, vanilla, and rum and continue to beat until thick and smooth. Stir in the pineapple. Line the bottom and sides of a buttered 9-inch springform pan with some of the ladyfingers, top with one third of the filling, and cover with half the remaining ladyfingers. Add half the remaining filling, cover with the rest of the ladyfingers, and top with the last of the filling. Sprinkle with walnuts, chocolate chips, and glaceed cherries. Cover the cake with plastic and chill overnight. Run a knife around the inside of the pan and release the sides. Transfer the cake to a serving dish.