Lemon Icebox Cake

Whisk pudding mix, 1½ cups milk and 2 teaspoons lemon zest in a large bowl until slightly thickened, about 2 minutes.

In another large bowl, whisk 2 cups cream and 1 teaspoon vanilla until stiff peaks form, 4 to 5 minutes. Fold 2 cups of the whipped cream into the pudding mixture until just combined. Cover and refrigerate the remaining whipped cream until ready to serve.

Line the bottom and long sides of a 9-by-5-inch loaf pan with parchment paper. Spread ½ cup pudding mixture in an even layer in the bottom of the prepared pan. Arrange 3½ graham cracker sheets in an even layer over the pudding mixture, breaking as needed to fit. Spread 1 cup pudding mixture evenly over the crackers. Repeat the layers 2 more times, using 3½ graham cracker sheets and 1 cup pudding mixture per layer, ending with graham crackers and the remaining pudding mixture (about ½ cup). Cover tightly with plastic wrap and refrigerate until the pudding is set and the crackers have softened, at least 4 hours or up to 12 hours.

Loosen the edges with a small offset spatula, if needed. Invert the cake onto a platter; remove and discard the parchment. Whisk the reserved whipped cream to return to stiff peaks, if needed. Dollop on top, spread over the top and sides, or serve on the side. Garnish with additional lemon zest, if desired.