In a small saucepan, combine freshly squeezed lemon juice, equal parts water, and granulated sugar. Heat over medium heat, stirring occasionally until the sugar fully dissolves.

In a large mixing bowl, whip cold heavy cream with powdered sugar and vanilla extract until soft peaks form.

In another bowl, gently beat together mascarpone cheese and lemon zest until smooth. Carefully fold the whipped cream into the mascarpone mixture.

Dip each ladyfinger cookie into the cooled lemon syrup for only 1-2 seconds. Arrange a layer of dipped ladyfingers in a 9x9-inch dish.

Spread half of the lemon mascarpone cream over the ladyfingers evenly using a spatula.

Repeat the dipping and layering process with more ladyfingers and the remaining mascarpone cream.

Cover with plastic wrap and refrigerate for at least 4-6 hours or overnight.

Before serving, garnish with extra lemon zest, candied lemon slices, or fresh mint leaves.