1. Prepare the Crust:

1. In a shallow dish, pour the limoncello. Quickly dip each ladyfinger or sponge cake slice into the limoncello, ensuring they are moist but not soggy, and arrange them in a single layer in a 9×13-inch baking dish.
2. In a large bowl, whisk together the mascarpone cheese, powdered sugar, lemon zest, lemon juice, and vanilla extract until smooth and creamy.
3. In a separate bowl, whip the heavy cream until stiff peaks form. Gently fold the whipped cream into the mascarpone mixture until fully combined.
4. Spread half of the mascarpone cream evenly over the first layer of soaked ladyfingers. Add another layer of dipped ladyfingers on top, then spread the remaining mascarpone cream over them.
5. Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight, to allow the flavors to meld and the cake to set.
6. Before serving, garnish with fresh berries and mint leaves. Slice and enjoy chilled.