In a large mixing bowl, combine mascarpone cheese, granulated sugar, fresh lemon juice, and lemon zest. Blend on medium speed until smooth and creamy, about 2-3 minutes.

In a separate bowl, whip the heavy cream on high speed until stiff peaks form, about 3-5 minutes. Gently fold the whipped cream into the mascarpone mixture.

Mix lemon juice with sugar in a shallow dish until dissolved. Dip each ladyfinger briefly into the lemon syrup and arrange in a single layer in your serving dish.

Spread half of the lemon mascarpone mixture over the ladyfingers, then repeat the layering process, finishing with the mascarpone mixture.

Cover with plastic wrap and chill for at least 4 hours, ideally overnight, to allow flavors to meld.

Garnish with lemon zest and whipped cream before serving. Cut into squares or scoops to serve chilled.