Preheat the oven to 350. Begin by making the caramel. Combine the sugar, water and lemon juice in a heavy bottomed saucepan and cook until the mixture is thick, bubbly and amber colored. This mixture will be very hot, don't touch. Pour the caramel into an 8-inch cake pan, swirling it around so it covers the entire bottom of the pan. Set aside. Prepare the custard. Whisk the orange juice, eggs, egg yolks, sugar, cream, and vanilla together until smooth. Pour the custard mixture over the caramel. Set inside of a larger pan, and pour enough hot water in the larger pan to reach halfway up the sides of the custard pan. Bake until the custard is firm, about 30 minutes. Allow to cool to room temperature, and refrigerate until needed. Using a knife, loosen the edges of the custard from the sides of the pan. Invert a plate on top of the pan and quickly flip it over. The caramel from the bottom of the pan forms its own sauce for this dish.