How to Make Creamy Lemon Icebox Cake

Step 1 - Make the lemon cream filling: Beat the softened cream cheese with the powdered sugar until smooth and fluffy, then mix in the lemon juice, lemon zest, and vanilla extract. The cream cheese should be completely at room temperature before you start, because cold cream cheese will leave lumps in the filling that are very difficult to smooth out once the whipped cream is folded in.

Step 2 - Whip the cream: In a separate chilled bowl, beat the heavy cream until stiff peaks form. This means the cream holds its shape firmly when you lift the whisk. Stop as soon as it reaches stiff peaks, because overwhipped cream can turn grainy and begin separating into butter.

Step 3 - Fold together: Gently fold the whipped cream into the lemon cream cheese mixture using a wide spatula. Use slow, deliberate strokes that go under and over the mixture rather than stirring in circles. The goal is to keep as much air in the whipped cream as possible so the filling stays light and airy rather than dense.

Step 4 - Layer the cake: Spread a thin layer of lemon cream on the bottom of a 9x13-inch dish, then add a single layer of graham crackers. Cover the crackers completely with a generous, even layer of the lemon filling. Repeat the layers until you run out of filling, finishing with a cream layer on top.

Step 5 - Chill overnight: Cover the dish and refrigerate the cake for at least 6 hours, though overnight is ideal. The longer it chills, the more completely the crackers soften and the more the flavors come together. Before serving, finish the top with extra lemon zest and a few dollops of whipped cream if you want a clean, finished presentation.