In a large bowl whip the cream with an electric mixer until slightly thickened. Add the vanilla extract and 2 tablespoons of the sugar and continue to whip until the cream holds soft peaks. In another bowl, cream together the remaining sugar , Limoncello and the mascarpone cheese for 30 seconds with an electric mixer. Using a rubber spatula, fold the whipped cream into the mascarpone.
One at a time, roll the ladyfingers in the Limoncello syrup and place in a single layer on the bottom of each Mason jar. You may need to break the cookies in half in order to fit the jars. Pour 1/3 of the Limoncello-mascarpone cream on top of the ladyfingers. Top with 1/3 of the blackberries. Dip and arrange a second layer of ladyfingers, and cover again with the next 1/3 of the Limoncello-mascarpone cream followed by blackberries. Follow this process one more time. Top the Mason jars with lemon zest, cover, and refrigerate for at least 6 hours.