Mascarpone-Zabaglione Mousse

Saturday night we went to a dinner party at Corey's coworker's house for some lovely authentic Italian food.  In keeping with the theme, I brought mascarpone-zabaglione mousse.  This is a recipe I have made several times before, but only years ago.  The recipe is courtesy of Biba Caggiano, a well known authentic Italian chef from Bologna.  In her book Biba's Taste of Italy: Recipes from the Homes, Trattorie, and Restaurants of Emilia-Romagna, she writes that this recipe comes from Trattoria del Cacciatore in the small hamlet of Frassinara, in the Parma countryside.  Of the cities I have visited in Italy, Parma is my favorite.  I imagine that anything coming from that area would be amazing - this mousse certainly is! This mousse takes some time to make, and needs to sit in the fridge for several hours, so get started in the morning.  It could be done the night before, but I think it's a little better when done on the same day.  It doesn't require a lot of ingredients, just time and attention.  The first step in making this mousse is to prepare the zabaglione, which on it's own is wonderful drizzled over strawberries.  The addition of mascarpone cheese turns it into a deliciously fluffy mousse.

Ingredients:
6 large eggs, at room temp
1/2C granulated sugar
Zest of 1 lemon
1/2C dark rum
1lb mascarpone cheese
Amaretti cookies, finely crushed
Grated semisweet chocolate

To prepare the zabaglione, put the eggs, sugar, and lemon zest in the bowl of an electric mixer and beat at medium speed for about 1 minute, until well blended. Turn the machine to high speed and beat until the mixture is pale yellow and has tripled in volume.
Transfer the mixture to a large heatproof bowl, or the top of a double boiler, and set it over a few inches of simmering water.  (Do not let the water boil or touch the bowl, or the eggs will curdle.)  Slowly add the rum, beating energetically with a large wire whisk (I use my immersion blender), and continue to whisk until the eggs have doubled in volume and the mixture is hot to the touch.  According to the recipe this should take about 10 minutes, but for me it usually takes about 20 minutes.  (This is when I am thankful to have my immersion blender.)  Place the bowl over a larger bowl half-filled with ice water, and whisk for a few minutes to cool.
Put the mascarpone in the bowl of the electric mixer, fitted with the paddle attachment, add about half of the zabaglione, and beat at medium speed just to combine.  Beat in the remaining zabaglione.  Do not overbeat.  Just as in making whipped cream or meringue, if you overbeat you will lose the airiness.
Spoon into dessert glasses.  Cover with plastic wrap and refrigerate for several hours, or overnight.  Just before serving, sprinkle the amaretti crumbs and the grated chocolate over the mousse.  (The recipe says to use either the amaretti cookies or the chocolate, but I like to use both - it just makes it that much more sinful.)

This recipe filled 6 stemless martini glasses for me, with a small amount leftover.  I think everyone enjoyed it, and it was all gone too quickly to take a photo.  Although Corey loved it, so I'm sure I'll be making it again.  It is a great dessert for a dinner party, since it needs to be done in advance anyway and is served chilled.

Those of you who know I have issues with dairy may be wondering how I can eat this mousse, but it doesn't bother me - apparently mascarpone cheese contains only a very small amount of lactose.  I also used some in our dinner last night - more to come on that.  It is high in fat, although not as high as butter, so I will have to resist the urge to keep it on hand.
I always buy all-natural free range eggs, which have a lower risk of salmonella.  I feel this is especially important here, where the eggs are basically only partially cooked.  I also used an organic lemon, since it is the zest that is needed, but not any wax or other substances :-).
When I first started making this mousse, I used this great dark rum brought to me from Haiti by my good friend Jen Costanza.  That rum is long gone and can be hard to find in stores here.  I did find it once...but not sure where.  Anyway, it is important to use dark rum, not spiced or black rum.  This time I used a new one I found - Pusser's British Navy Rum from Barbados.  I didn't want to get a really cheap one, since I suspect it may be consumed out of a glass as well.  And I try not to cook with something I wouldn't drink.

Who's going to try this?  Has anyone made this before?