1. Prepare the Crust:

1. Melt the dark chocolate in a heatproof bowl over simmering water. Allow to cool slightly, then fold in two egg yolks. Whip two egg whites until stiff peaks form, then gently fold into the chocolate mixture. Pour into the bottom of a springform pan and refrigerate.
2. Repeat the process with the milk chocolate: melt, add two yolks, and fold in whipped egg whites. Pour over the set dark chocolate layer and return to the refrigerator.
3. For the final layer, repeat with the white chocolate and the remaining eggs. After pouring the white chocolate layer on, chill the cake for at least 4 hours or overnight to set completely.