White Chocolate Tiramisù
Adapted from Bon Appétit
Serves at least 18

I made this, as the recipe suggests, in a 13×9-inch Pyrex pan.  The filling extends well beyond the pan and kind of sticks to the foil that you use to cover it.  It turns out fine, but I thought next time I would add another 6 ounces of ladyfingers and make the whole dessert in a bigger pan.  I used my hand mixer for the egg yolks, my stand mixer for the cream cheese, then my hand mixer again for the egg whites and also for the cream.

2½ cups hot water plus 2 tbsp. water
¼ cup instant espresso powder
6 tbsp. dark rum
8 ounces good-quality white chocolate, chopped
8 large egg yolks
1¼ pounds cream cheese (two and a half 8-ounce packages), room temperature
4 large egg whites
¾ cups sugar
1½ cups chilled whipping cream
90 soft ladyfingers from four 3-ounce packages
2 tbsp. unsweetened cocoa powder

Pour 2½ cups hot water into medium bowl.  Add espresso powder; stir to dissolve.  Stir in rum.  Cool espresso mixture.  Place chocolate in medium bowl.  Set bowl over saucepan of simmering water and stir until melted and smooth.

Combine egg yolks, powdered sugar, and remaining two tablespoons of water in medium bowl.  Set over saucepan of simmering water and whisk constantly, until mixture thickens slightly and reaches 160ºF, about 6 minutes.  Remove bowl from over water.  Using electric mixer, beat egg yolk mixture until cool and thick, about 5 minutes.  Using electric mixer, beat cream cheese in large bowl until smooth.  Beat barely lukewarm melted chocolate into cream cheese.  Fold egg yolk mixture into cream cheese mixture.

Using electric mixer fitted with clean dry beaters, beat egg whites in another large bowl to soft peaks.  Gradually add ¾ cup sugar, beating until stiff peaks form.  Fold 1/3 of beaten egg white mixture into cream cheese mixture to lighten.  Fold in remaining egg white mixture.  Beat whipping cream in medium bowl to medium-stiff peaks.  Gently fold whipped cream into cream cheese mixture, creating mousse.

Lightly dip 1/3 of ladyfingers 1 at a time in espresso-rum mixture and place in single layer in bottom of 13-9-2-inch glass baking dish.  Spoon 1/3 of mousse over ladyfingers, spreading evenly.  Dip next 1/3 of ladyfingers in espresso mixture and place atop mousse.  Top ladyfingers with another 1/3 of mousse.  Repeat with remaining ladyfingers, espresso mixture and mousse.  Sift cocoa powder over top of tiramisù.  Cover; chill overnight.