In the bowl of an electric mixer fitted with the whisk attachment, whip the mascarpone cheese and sugar on medium speed until well combined, about one minute, scraping down the bowl as necessary. Add 1 cup of the lemon curd and lemon juice and mix until well combined, about one minute. Scrape down bowl. Add the heavy cream and mix on low speed until combined and then slowly raise the speed, until it forms firm peaks.
Take the ring from an 8-inch springform pan (you don't need the bottom piece) and place directly on a large plate or cake stand. Arrange the ginger thin cookies in a flat layer, approximately 9-10 cookies for each layer. (I lined the perimeter of the ring with the cookies first and then the center. You'll need to break some cookies to fill the center.) Spread one cup of the filling evenly over the cookies. Add another layer of cookies and filling until you have a total of 5 layers each of cookies and filling, ending with a layer of the filling. Make sure the top layer is smooth as much as possible.
Place the remaining ¼ cup of lemon curd in a plastic ziploc bag and snip off one corner. Squeeze several thin lines of the lemon curd across the top of the cake. Drag a wooden skewer perpendicularly through the lines to create a marble design.
Refrigerate cake overnight.
Run a small paring knife around the outside of the cake and remove the sides of the pan. Cut in to wedges and serve cold.