Spread half of the remaining orange curd cream on top, then top with
the final cake layer, top side up.
Press on
final cake layer, and frost top and sides of cake with remaining frosting.
Add
the final cake layer and pour the rest of the icing over the top of the cake, letting it run down the sides.
Top with
the final cake layer, soak with the remaining syrup, and refrigerate until the cake is firm, 1 to 2 hours, then dust with cocoa powder.
Sit
the final cake layer on top then completely cover the top and sides with the remaining zabaglione mix, using a palette knife to swirl the mixture about smoothly and confidently.