Make the Cream Beat the butter and powdered sugar until light and fluffy. Add egg yolks one at a time (if using), then mix in vanilla. Set aside.
Soak the Biscuits Dip each biscuit briefly in the coffee — just enough to soften, not soak.
Layer the Cake On a serving plate, arrange a layer of soaked biscuits in a circle. Spread a thin layer of cream on top. Repeat layers (biscuits + cream) until you have 5–6 layers.
Finish & Chill Cover the top and sides with remaining cream. Garnish with crushed biscuits or a sprinkle of cinnamon. Refrigerate for at least 4 hours (overnight is best).
