Beat the egg yolks with the sugar until the sugar has dissolved and the mixture is light and fluffy and leaves a ribbon trail when dropped from the whisk.
Add the mascarpone and beat until the mixture is smooth.
Whisk the egg whites in a clean glass bowl, using a wire whisk or hand beaters, until soft peaks form. Fold into the mascarpone mixture.
Pour the coffee into a shallow dish and add the Kahlua. Dip enough biscuits to cover the base of a 25cm sq dish into the coffee, careful not to over saturate. Arrange the biscuits in one tightly packed layer in the bottom of the dish.
Spread half the mascarpone mixture over the layer of biscuits. Repeat with another layer of biscuits and mascarpone and refrigerate for at least 6 hours before serving.
Upon serving, dust top with finely grated chocolate.
Reprinted with permission of Carl Penn
, Exec Chef at Peddlars on The Bend