Bring 1 1/2 cups water to a boil, and remove from heat. Add
coffee; cover and let stand for 10 minutes. Strain through a
cheesecloth-lined sieve into a medium bowl; discard solids.
Cover and refrigerate until needed.
Combine 1/4 cup sugar, egg yolks, and 1 tablespoon Kahlua in
the top of a double boiler, stirring well with a whisk. Cook over
simmering water, whisking constantly, until thick and candy
thermometer registers 160 degrees (about 9 minutes). Remove
from heat; refrigerate 10 minutes.
Place egg whites in a large bowl; beat with a mixer at high speed
until medium peaks form. Combine the remaining 1/4 cup sugar
and 2 tablespoons water in a small saucepan, and bring to a boil.
Cook, without stirring, until the candy thermometer registers
250 degrees. With mixer on low speed, carefully pour hot syrup
over egg whites. Gradually increase speed to high; beat for 2
minutes or until stiff peaks form (do not overmix).
Combine egg yolk mixture, cream cheese, and mascarpone cheese in a large bowl, and
beat with a mixer at medium speed until smooth. Gently stir 1/4 of egg white mixture into
cream cheese mixture; gently fold remaining egg white mixture into cream cheese mixture.
Add remaining 1 tablespoon Kahlua to coffee. Quickly dip 12 ladyfingers into coffee
mixture. Arrange in the bottom of an 11 by 7 inch baking dish. Spread half of cream
cheese mixture over ladyfingers. Sprinkle with half of chocolate. Repeat procedure with
the remaining ladyfingers, coffee mixture, and cream cheese mixture. Sprinkle with
remaining chocolate. Cover and chill at least 2 hours.