01 - Combine water, lemon juice, and sugar in a small saucepan. Heat over medium, stirring until the sugar fully dissolves. Remove from heat and let cool completely.
02 - In a large mixing bowl, whisk together the cold mascarpone, heavy cream, sugar, lemon zest, lemon juice, and vanilla extract until smooth and thickened.
03 - Briefly dip each ladyfinger into the cooled lemon syrup without soaking. Arrange a single layer of dipped ladyfingers in the bottom of an 8x8-inch dish.
04 - Spread half of the lemon cream evenly over the bottom layer of ladyfingers using a spatula.
05 - Place a second layer of quickly dipped ladyfingers over the cream. Top with the remaining lemon cream and smooth the surface.
06 - Cover the dish tightly with plastic wrap and refrigerate for at least 4 hours, or overnight for the best texture and flavor.
07 - Before serving, finish with a sprinkle of lemon zest and optional white chocolate curls or mint leaves. Serve cold.