In a small bowl, soak the raisins in the rum for 1/2 hour. Drain, reserving the raisins and 2 tablespoons of the rum separately. Set aside.
Preheat the oven to 350 degrees. In a large bowl, beat the sugar and egg with an electric mixer, until creamy. Add the cream cheese and beat until well incorporated. Beat in the ricotta cheese. Stir in all but 3 tablespoons of the raisins and reserved rum. Pour the cheese mixture into the graham cracker crust and sprinkle with the reserved raisins. Bake for 25-30 minutes, until the center doesn't juggle when the pan is moved. remove from the oven and cool to room temperature before serving.