Molten Chocolate Tuxedo Cakes

Preheat oven to 325u0b0F.
Butter and flour six 6-ounce custard cups.
Melt the bittersweet chocolate in a double boiler or metal bowl set over saucepan of simmering water; stir until smooth. Remove from heat and let cool slightly.
In a separate bowl, melt the white chocolate and stir until smooth. Remove from heat and let cool slightly.
Beat the eggs, egg yolks and sugar in bowl until pale and thick, about 10 minutes. Add the melted butter and mix to combine. Reduce speed and gradually beat in the flour.
Take 3/4 cup of the batter into a separate bowl and add the white chocolate and Grand Marnier. Beat until thick and glossy, about 5 minutes. Place in the refrigerator to chill for at least 20 minutes. When fully chilled, remove from the refrigerator and form into 6 balls.
Take the remaining batter and add the bittersweet chocolate mixture. Beat until thick and glossy, about 5 minutes. Leave at room temperature until the white chocolate is chilled.
Divide 1/2 of the bittersweet chocolate batter among the prepared cups. Drop a white chocolate ball into each cup, pressing slightly so that it is 1/2 submerged into the chocolate batter, but not touching the bottom of the cup. Top with the remaining bittersweet chocolate batter, making sure to cover the white chocolate completely.
Bake until cakes are set around edges but center moves slightly when cup is moved, about 13 minutes. Cool slightly. Run sharp knife around edge of cups. Turn out onto plates. Serve warm with ice cream.