-Unsweetened cocoa -for garnish, sifted. Beat heavy cream with sugar until stiff. Set aside. Using same beater, beat together ricotta, sugar and sour cream. Gently fold cream and cheese mixes together; add rum. Line an 8 x l3 inch baking dish with lady fingers that have been soaked with the coffee. Pour cream mix over the cake and let sit at least 4 hours or overnight. When set, top with unsweetened cocoa. This is from the Sacred Heart Church of Georgetown CT. The authentic tiramisu (pick me up) calls for marscapone cheese, which is relatively hard to get and expensive. I have found the following substitute works well. Be sure you use firm or stale lady fingers so it doesn't get mushy.