Combine 3 egg yolks, 1 tablespoon Espresso, sugar, and Cognac in a large mixing bowl.
Beat 2 to 3 minutes.
Add Mascarpone and beat 3 to 5 minutes until consistency is smooth.
In another bowl, combine 3 egg whites and a pinch of sugar. Beat until mixture forms stiff peaks.
Gently fold into Mascarpone mixture.
Pour rest of Espresso into flat dish, dip one side of each Lady Finger, and layer on bottom of serving dish.
Spread 1/3 of Mascarpone mixture and sprinkle with cocoa.
Continue layering and finish with a Mascarpone layer.
Sprinkle w/cocoa & refrigerate 1 hour before serving.