Gently heat the milk and cream with the lemon peel until just below boiling point. Remove from the heat and leave to infuse for about 20 minutes, then discard the peel.
Whisk the egg yolks with the sugar and cornflour until pale and slightly thickened. Reheat the infused milk mixture, then slowly pour it into the egg mixture, whisking continuously.
Return everything to a clean saucepan and cook over low heat, stirring constantly, until it thickens into a smooth custard. Do not allow it to boil, or it may curdle. This takes about 4–5 minutes. Transfer to a bowl, cover the surface with cling film to prevent a skin forming, and leave to cool completely.
Cut the ladyfingers in half, spread lightly with lemon curd, then cut into smaller pieces. Arrange them in the base of a glass serving dish and drizzle evenly with the limoncello.
Scoop out the pulp of the passion fruit and scatter it over the soaked sponge. Pour the cooled lemon custard on top, smoothing the surface.
Refrigerate for at least 3–4 hours, or preferably overnight, to allow the layers to set and the flavours to develop.
About an hour before serving, make the Lemon Cream Topping: whip the cream with the sugar, lemon zest, lemon juice and white wine until soft but stable peaks form. It should hold its shape but remain light and silky.
Spread the lemon cream over the chilled trifle and return to the fridge for another hour.
Decorate just before serving with edible sprinkles or fresh fruit.