Pour the milk into a shallow bowl. Add granulated sugar and half of the fresh lemon juice. Stir well until the sugar dissolves completely. This mixture gives the ladyfingers a soft texture and gentle lemon flavor.

Pour heavy whipping cream into a large mixing bowl. Use an electric mixer to whip until soft peaks form. The cream should look fluffy and smooth without becoming too stiff or grainy.

In another bowl, combine mascarpone cheese, powdered sugar, vanilla extract, lemon zest, and remaining lemon juice. Mix until creamy and smooth. Fold the whipped cream gently into the mascarpone mixture using a rubber spatula.

Quickly dip each ladyfinger into the lemon milk mixture for a few seconds. Do not soak them too long. Over-soaked cookies become mushy and fall apart while layering the dessert.

Arrange half of the soaked ladyfingers in the bottom of the baking dish. Spread half of the mascarpone mixture evenly over the cookies. Add small spoonfuls of lemon curd across the creamy layer.

Repeat the process with remaining ladyfingers, mascarpone filling, and lemon curd. Smooth the top gently using a spatula. The creamy layers should look even and soft with lemon curd throughout.

Cover the dish tightly and refrigerate for at least four hours. Chilling helps the flavors blend together beautifully. Before serving, garnish with extra lemon zest and fresh lemon slices for a bright finish.