Preheat oven to 350 degrees. Coat a 9-inch square baking pan with cooking spray. Pulse graham crackers in a food processor until they turn to crumbs. Stir together graham cracker crumbs and melted butter. Pour into the prepared baking pan and press evenly down with the bottom of a glass. Press into bottom of pan. Bake until crust is just brown around the edges then set aside to cool, about 3-5 minutes. While crust is baking, beat cream cheese and tofu with a mixer on medium speed, about 2 minutes. Add the sugar and eggnog, then mix another 2 minutes. Add lemon juice, brandy, vanilla, nutmeg and corn starch and beat until mixture is smooth. Pour filling over crust then bake until just set, about 50-55 minutes. Filling will not be completely firm when you remove the baking pan from the oven and that's ok. Transfer to a wire rack and let cool for 30 minutes. Refrigerate for at least 3 hours or overnight. Cut into 2-by-2-inch bars. Lightly dust tops of bars with freshly grated nutmeg before serving.