Make the whipped cream then mix in mascarpone. Set in the fridge until ready to use
Add a layer of ladyfinger to the bottom of a baking dish. Drizzle eggnog on both sides of the ladyfingers
Add half the whipped cream mascarpone mix and spread it evenly to cover all ladyfingers
Dust with cinnamon and cocoa powder.
Sprinkle crushed pecans
Repeat for a second layer in the exact same manner as above.
Finish the cake with a generous layer of cocoa powder and pecans. Decorate with whipped cream. Refrigerate for at least 4 hours (best overnight) before serving.