01 - Combine water, lemon juice, and sugar in a small saucepan. Heat over medium heat, stirring continuously, until the sugar has fully dissolved. Remove from heat and let cool to room temperature before using.
02 - In a large mixing bowl, combine cold mascarpone, heavy cream, granulated sugar, lemon zest, lemon juice, and vanilla extract. Whisk with an electric mixer or hand whisk until the mixture is smooth, thick, and holds soft peaks.
03 - Working quickly, briefly dip each ladyfinger into the cooled lemon syrup—do not soak, just a quick pass on each side. Arrange the dipped ladyfingers in a single even layer across the bottom of an 8x8-inch dish.
04 - Spread half of the lemon cream evenly over the first layer of ladyfingers using a spatula, ensuring full coverage to the edges.
05 - Dip a second batch of ladyfingers in the lemon syrup using the same quick-dip method and arrange them evenly over the first cream layer.
06 - Spread the remaining lemon cream over the second ladyfinger layer, smoothing the surface into an even, clean finish with a spatula.
07 - Cover the dish tightly with plastic wrap and refrigerate for at least 4 hours, or overnight for the best flavor and texture development.
08 - Just before serving, finish with a sprinkle of fresh lemon zest and optional white chocolate curls or mint leaves. Serve directly from the dish while chilled.