I adore the light feel and fresh flavor of lemon desserts, especially during the summer. I designed this recipe to evoke the flavors of lemon cheesecake and the texture of tiramisu with delicate layers of mousse and ladyfingers. The best part? As with an old-fashioned icebox cake, all you need is a refrigerator, no oven required!
Prepare a 9-inch springform pan by flipping the base so that the lip is on the bottom of the
pan and then latch the pan in place. Spray the inside lightly with nonstick spray.
For the crust: Combine the cookie crumbs and lemon zest in a medium bowl and toss to combine. Add the butter and toss to combine. Press the mixture firmly over the bottom of the prepared pan. Set aside.
For the mousse: In the bowl of a stand mixer fitted with the whisk attachment, whip the cream on medium-high speed until medium peaks form. Transfer the cream to a separate large bowl and set aside.
Combine the mascarpone, confectioners' sugar, lemon zest, lemon juice, lemon extract, vanilla and salt in the same bowl used to whip the cream. Beat on medium speed until smooth, about 1 minute. Scrape the bowl and whisk attachment and continue to beat until thoroughly combined, about 30 seconds longer. Remove the bowl from the mixer and use a rubber spatula to fold about a third of the whipped cream into the mascarpone cream. Fold the remaining cream into the mascarpone mixture in thirds.
For assembly: Spread a third of the lemon mousse over the crumb crust. Arrange half of the ladyfingers in a single layer over the mousse. Add another third of the mousse and spread it evenly over the top. Add another layer of lady fingers. Spread the remaining mousse over the ladyfingers and smooth the top. Refrigerate the cake at least 6 hours or overnight.
To serve, gently run a spatula between the mousse and the edge of the springform pan. Unlatch the pan and slide the cake off the base and onto a serving platter (or serve the cake right from the springform bottom). Smooth the sides of the cake with an offset spatula if desired. Sprinkle the coarsely crushed cookie crumbs in a ring around the outer edge of the top of the cake. Serve chilled.