110-ounce jar good-quality store-bought lemon curd
Put the cream, mascarpone cheese, powdered sugar, limoncello, and vanilla in a mixer fitted with a whisk attachment. Start the mixer on low, then increase the speed to high and whip until stiff peaks form.
Place a layer of vanilla wafers in the bottom of a 9-inch springform pan. Break some of the cookies if you have to, making sure most of the bottom is covered.
Spread 1/3 of the whipped cream mixture on top of the cookies and then top with another layer of cookies. Spread the lemon curd over the cookies. Top with 1/3 of the whipped cream mixture, another layer of cookies, and finish with the remaining whipped cream mixture.
Cover the top of the cake with plastic wrap and refrigerate overnight or up to 48 hours. (I think the cake is at its best at around the 24-hour mark.)
Run a sharp knife around the edge of the cake and release the side of the pan.