In a large mixing bowl, whip the heavy cream, 1/2 cup granulated sugar, and vanilla extract until it forms stiff peaks.

In another bowl, blend the mascarpone cheese until smooth, then fold in the whipped cream mixture gently until fully combined.

Prepare the lemon soak by heating 1/4 cup water, 3/4 cup granulated sugar, and 1/2 cup lemon juice in a saucepan over medium heat until the sugar dissolves. Allow to cool.

Spread half of the lemon curd over the soaked ladyfingers.

Layer half of the mascarpone mixture over the lemon curd.

Repeat with another layer of soaked ladyfingers, lemon curd, and mascarpone mixture.

Cover and refrigerate for at least 6 hours, or overnight, to allow the flavors to meld and the dessert to set.

Before serving, garnish with lemon zest if desired.