How to Make It
Coat a 2 1/2-quart glass bowl with nonstick spray and line with plastic wrap, allowing 6 inches of overhang all around.
In a medium bowl, whisk 1/2 cup of the sugar with the gelatin. Stir in the hot water and let stand for 3 minutes, then whisk to dissolve the sugar and gelatin.
In a stand mixer fitted with the paddle, beat the ricotta with the cream cheese at medium speed until smooth. With the machine on, gradually beat in the gelatin mixture, then beat in the lemon zest, lemon juice and vanilla. Scrape the cheesecake mixture into the prepared bowl and cover with the overhanging plastic. Refrigerate until nearly set, about 1 hour.
Meanwhile, in a food processor, pulse the graham crackers with the cinnamon until fine crumbs form. Transfer to a heatproof medium bowl.
In a medium saucepan, combine the remaining 1 cup of sugar with 1/2 cup of water and cook over moderate heat until it reaches 330° on a candy thermometer, 5 to 7 minutes. Remove from the heat and whisk in the butter. Immediately pour over the graham cracker crumbs and stir quickly until evenly moistened; clumps will form.
Uncover the cheesecake and sprinkle the graham cracker mixture evenly on top, packing it gently onto the surface of the cake. Cover and refrigerate until the cake is completely set, at least 2 hours or overnight.
In a large saucepan, melt the butter with the sugar. Cook over moderate heat, swirling the pan, until a very light caramel forms, 5 to 7 minutes. Stir in the cinnamon, allspice and salt and cook, swirling, for 30 seconds. Add the amaretto and rum and, very carefully, using a long-handled match, ignite the alcohol. When the flame subsides, stir in the bananas. Let cool.
Unwrap the cake and carefully invert onto a rimmed serving plate. Spoon the bananas Foster over the top and serve right away.