01 - Combine water, lemon juice, and sugar in a small saucepan. Heat over medium heat, stirring until the sugar fully dissolves. Remove from heat and let cool completely.
02 - In a large mixing bowl, combine cold mascarpone, heavy cream, sugar, lemon zest, lemon juice, and vanilla extract. Beat with an electric mixer or whisk until smooth, thick, and holds soft peaks.
03 - Quickly dip each ladyfinger into the cooled lemon syrup — just a brief pass, do not soak. Arrange a single layer of dipped ladyfingers across the bottom of an 8x8-inch dish.
04 - Evenly spread half of the lemon cream over the first layer of ladyfingers, using a spatula to smooth the surface.
05 - Repeat the quick-dip process with remaining ladyfingers and arrange a second layer on top of the cream.
06 - Spread the remaining lemon cream over the second biscuit layer, smoothing the top into an even surface.
07 - Cover tightly with plastic wrap and refrigerate for at least 4 hours, or overnight for the best texture and flavor integration.
08 - Before serving, finish with a sprinkle of fresh lemon zest and optional white chocolate curls or mint leaves. Serve cold.