Layer Ladyfingers: Dip each ladyfinger briefly in the Limoncello syrup and place in the bottom of an 11×8-inch pan (or similar size).
Add Mascarpone: Spread half of the Limoncello mascarpone cream over the ladyfingers.
Add Lemon Curd: Spread ½ cup of lemon curd over the mascarpone layer.
Repeat Layers: Dip more ladyfingers in the syrup and place on top of the lemon curd. Spread the remaining mascarpone cream over the ladyfingers.
Decorate: If you have leftover mascarpone, pipe it around the edges of the dish. If not, top with whipped cream. Spoon the remaining lemon curd in the center and sprinkle with lemon zest.
Chill: Refrigerate for at least 4 hours before serving.