In a small saucepan, combine ½ cup of freshly squeezed lemon juice, ½ cup of water, and ½ cup of granulated sugar over medium heat. Stir continuously until the sugar is dissolved, about 3-4 minutes. Remove from heat and let cool completely.

In a large mixing bowl, pour in 1 cup of cold heavy whipping cream and add ½ cup of powdered sugar along with 1 teaspoon of vanilla extract. Use an electric mixer to whip on medium-high speed until soft peaks form, about 3-5 minutes. In another bowl, beat 1 cup of room-temperature mascarpone cheese with the zest of a lemon until smooth and fluffy. Gently fold in the whipped cream mixture to combine.

Grab a 9×9-inch dish and briefly dip each ladyfinger cookie in the cooled lemon syrup for 1-2 seconds. Lay half of the soaked ladyfingers in the bottom of the dish. Spread half of your mascarpone cream over the ladyfingers, smoothing it evenly.

Continue by dipping the remaining ladyfingers in the lemon syrup and placing them over the first layer of cream. Spread the second half of the mascarpone cream on top, ensuring it's evenly distributed.

Cover the assembled Tiramisu with plastic wrap and place in the refrigerator. Let it chill for at least 4-6 hours, preferably overnight.

Before serving, garnish with additional lemon zest, fresh mint leaves, or candied lemon slices. Slice generously and serve chilled.