In a large bowl beat the cream until stiff peaks form.
In a medium / large bowl add the mascarpone and sugar, mix to combine, add the lemon juice a zest a little at a time beating to combine.
Fold the mascarpone mixture into the whipped cream until completely combined. Cover the bowl and chill 20-30 minutes.
In a small bowl combine the water and Limoncello or lemon juice.
In four small/medium serving dishes or glasses layer starting with a spoonful of the cream filling, then lady fingers dipped in the Limoncello mixture, continue with another layer. Repeat with the other glasses. Refrigerate 30 minutes before serving. Top with lemon zest or chopped white chocolate before serving if desired. Enjoy!
Notes
Since this lemon mascarpone dessert needs time to chill it is a great make ahead dessert! To make in advance, prepare as directed and store covered tightly in the refrigerator up to two days before serving.To store leftover parfaits, cover and store up to three days, although I find it best within 2 days.Do not freeze leftovers as texture will change upon thawing.