Combine both chocolates in a medium bowl set over simmering water and heat until melted, stirring occasionally. Set aside to cool to lukewarm.

In a large bowl, whip 1 cup of the cream to just beyond soft peaks but not quite stiff. Set aside, refrigerated.

In a medium bowl whisk the egg yolks until smooth. Set the bowl over a pot of simmering water. Add 2 tablespoons of the Frangelico, the coffee, and melted chocolate and cook, whisking, until pale and thick and forms a ribbon.

In another bowl, beat the egg whites until they form soft peaks. Add 2 tablespoons of the confectioners' sugar little by little until whites are stiff and glossy but not dry. Set aside.

Using a large rubber spatula, fold in the whipped cream. Very gently fold in the egg whites.

Spoon the mousse into individual bowls or festive glasses such as martini glasses, cover, and refrigerate for at least 8 hours before serving.

When you are ready to serve the mousse, make the Toasted Hazelnut Cream by placing the remaining 1/2 cup of heavy cream in a medium bowl and whipping to soft peaks. Add the remaining tablespoon of confectioners' sugar, the remaining tablespoon of Frangelico, and the vanilla, and continue to whip until just stiff. Serve a healthy dollop on top of each mousse, and top with some of the toasted hazelnuts.