Beat mascarpone with Eggbeaters, sugar, vanilla, and Kahlua to taste until smooth and thick.
Whip cream with powdered sugar to stiff peaks. Fold into mascarpone mixture and chill well.
Dip one side of ladyfingers quickly into strong coffee or espresso, layer coffee side up in trifle bowl, casserole dish, or preferred container. Dust with cocoa powder. Layer cream on top. Repeat until ingredients are used, ending with cream and cocoa powder. Shave chocolate on top and refrigerate 8 hours or overnight.