Prepare the lemon syrup by simmering sugar, lemon juice, lemon peel, and water until dissolved, then let it cool completely.

Whip the heavy cream in a chilled bowl until stiff peaks form, being careful not to overmix.

In a separate bowl, mix mascarpone, lemon curd, and vanilla until smooth and creamy.

Fold the whipped cream gently into the mascarpone mixture in two stages to keep it light.

Quickly dip ladyfingers in the cooled syrup and arrange them in a single layer in a baking dish.

Spread half of the cream mixture evenly over the ladyfingers.

Add another layer of dipped ladyfingers, then spread the remaining cream on top and refrigerate overnight.

Spread lemon curd over the top, chill briefly, slice, pipe reserved cream if desired, and finish with lemon zest before serving.