Rich, dense and fudgy, this cake is for the serious chocolate lover. It's best served at room temperature, however, it can be stored in the refrigerator if made ahead. Drizzle with melted chocolate before serving.
Note Tuaca is an Italian liqueur made from brandy with citrus and vanilla accents. It's available from speciality liquor stores. If unavailable, substitute with brandy or whisky. An offset spatula has a blade that dips away from the handle at an angle and is perfect for icing cakes. Available from kitchenware stores.