In a large mixing bowl, pour in the heavy cream and use an electric mixer to beat it on medium speed until soft peaks form, about 3-4 minutes. Gradually add in the confectioners' sugar, continuing to mix until fully incorporated and the cream is light and fluffy. Set aside.

In another bowl, combine the mascarpone, lemon zest, and kosher salt. Mix until completely smooth. Gently fold in the whipped cream in two additions.

Pour the lemonade into a shallow dish, adding the limoncello. Quickly dip each ladyfinger into the mixture and lay them in a layer in your serving dish.

Spread half of the mascarpone mixture over the ladyfingers, then add half of the lemon curd in dollops. Repeat with remaining ingredients, finishing with mascarpone.

Cover the assembled tiramisu with plastic wrap and refrigerate for 8-12 hours to let flavors meld.

Garnish with additional lemon curd and a sprinkle of lemon zest upon serving.