Torta Di Zabaglione (Harry'S Bar)

Make Zabaglione filling: Using an electric beater, beat egg yolks for a minute. Add the sugar and beat until the mixture is thick and pale yellow. Add the flour 1 tbsp at a time and beat it in thoroughly. Beat in the white wine and sherry. Put the mixture in a heavy bottomed saucepan over medium heat and cook it, stirring constantly, until it is just about to boil. Let the custard cool, whisking it from time to time to keep a crust from forming, and refrigerate it, covered, for at least 2 hours. You can make this filling up to 24 hours in advance.
When ready to assemble cake, whip the cream until very stiff and combine it gently but thoroughly with the zabaglione.
Assemble the cake: Put the bottom layer of cake on a platter and spread half the filling over it. Top it with another layer of cake and, using a board or the bottom of a cake pan, press gently on the cake. A little filling will ooze out, which you wll use to frost the sides of the cake. Put all but 1/2 cup or so of the remaining filling on the cake, top it with another layer and again press down gently on it. Using a spatula, spread the filling evenly over the sides of the cake, using the extra you have saved to make a fairly thick coat.
Place meringues evenly around the sides of the cake for decoration. Sift confectioners' sugar over the top of the cake in a thick layer that covers it completely. Refrigerate cake until serving time.