36 ladyfingers
1/4 cup cold coffee
1 teaspoon rum extract
1 tablespoon instant espresso granules 
3/4 cup sugar
2 egg whites
2 tablespoons cold water
Pinch of cream of tartar
1/2 cup yogurt cheese 
1/2 cup softened nonfat cream cheese
1 teaspoon vanilla
2 tablespoons unsweetened cocoa powder

Spread the ladyfingers on a baking sheet and toast them at 350° for 6 to 8 minutes, or until dry.
In a small bowl, stir together the coffee, rum extract and espresso granules.
Brush over the flat side of the ladyfingers and set aside.
Bring 1" of water to a simmer in a large saucepan.
In a heatproof mixing bowl that will fit over the saucepan, combine the sugar, egg whites, water and cream of tartar.
Set the bowl over the simmering water and beat with an electric mixer at low speed for 4 to 5 minutes, or until a candy thermometer inserted in the mixture registers 140° Increase the speed to high and continue beating over the heat for 3 minutes, or until the mixture is thick and smooth enough that when you lift the beaters, a flat trail of egg white mixture stretches between the beaters and the bowl, like a glossy ribbon.
Remove the bowl from the heat and beat for 4 minutes, or until cool and fluffy.
Set aside.
In a large bowl, beat the yogurt cheese and cream cheese until creamy.
Add the egg white mixture and the vanilla.
Beat until smooth, occasionally scraping down the sides of the bowl.
Line the bottom and sides of a medium souffle dish or glass bowl with some of the ladyfingers.
Spoon in one-fourth of the filling and top with a layer of ladyfingers.
Repeat with 2 more layers, arranging the fourth layer of ladyfingers over the top and trimming to fit if necessary.
Top with the remaining filling.
Cover and refrigerate for at least 30 minutes or overnight.
Dust with the cocoa.