Combine the mascarpone and sugar in a bowl and stir to dissolve. In a stand mixer, whip the whipping cream until stiff peaks form, 2-3 minutes. Fold the whipped cream in to the mascarpone.
Pour the beer into a shallow bowl. Dip the ladyfingers into the beer, flipping once. Don’t soak them too long or they’ll fall apart.
Place the ladyfingers in a tight single layer on the bottom of your cup, breaking into pieces of necessary. Spoon on a bit of the mascarpone and smooth out. Dust with dark cocoa powder. Repeat until you reach the top of your cup. Finish with a dusting of cocoa. Wrap up and refrigerate for at least 12 hours before serving.