Looks like an impossibly elaborate cake but all you need to do is layer in a mixing bowl.
Zuccotto / Creamy Italian Dessert Cake / Yield: 12 servings
Ing sponge cake baked in a 9" tin (can use leftover cake) 2 oz plus 1 Tb Grand Marnier or Cointreau, bit Kahlua 4 oz best semisweet chocolate, broken into pieces 2 oz grated dk chocolate 18 oz h/cream (10 oz for filling, 8 oz to decorate) 4 tsp (divided) instant espresso-coffee powder 1 recipe of Italian pastry cream (below) more grated chocolate or chocolate curls for decor Italian Pastry Cream (Crema Pasticcera) 4 egg yolks 6 tbl sugar 2 Tb flour 17 oz milk 1 tsp vanilla
Steps Line 2 1/2 qt bowl w/ saran much larger than you need to cover top. Place cake slice in bottom; cake strips to line sides. Sprinkle cake w/ Kahlua. Pastry Cream Off heat, stir yolks and sugar briskly w/ wooden spoon. Add flour a little at a time to incorporate. Heat milk to boiling and add vanilla; add hot milk little at a time, mixing well after adding. Once milk is added, put pot on med heat and continue to stir. When mixture comes to a boil, cook 3-4 min then remove offheat. Keep stirring as it cools to prevent skin. Micro-melt Chocolate. Set aside. Zuccotto Filling beat 10 oz h/cream w/ instant coffee powder to stiff peaks; set aside. To the cooled pastry cream, add 1 Tb Grand Marnier, 2 oz grated chocolate and whipped coffee cream. Fold mixture until completely combined.
Set 2/3 of mixture into cake-lined bowl almost reaching the top, but not completely. Leave hollow in the middle. Add melted chocolate to remaining cream. Mix well til color is uniform, then fill center. Close up bottom w/ cake pieces. Sprinkle w/ liqueur, then saran and refrigerate 6-24 hours.
Decorate Beat 8 oz h/cream, w/ 2 tsp coffee powder, 2 tbl sugar to stiff peaks. Spread all over w/ swirls or peaks on cake inverted on cake stand. Sprinkle w/ chocolate shavings. Refrigerate an hour or so, or serve immediately.