Strawberry gingersnap icebox cake. Picture by Andrew Scrivani for The New York Times.
The elements

The cakey layers give an icebox cake its structure and, well, cakey-ness. This element can take many forms, such as cookies, digestive biscuits or ladyfingers. 

Cookies should be thin and crispy, and are best layered with whipped cream. (Thicker cookies, such as biscotti and some shortbread, remain a bit too toothsome even after the requisite rest in the fridge.) Digestive biscuits and ladyfingers (either the soft or crispy variety) work well with both whipped cream and pudding. If you’re feeling frisky, layer your cake with chocolate biscuits or cinnamon ones, peanut butter cookies or even ginger snaps.

The assembly

When choosing a pan or shape for your icebox cake, the possibilities are deliciously endless, provided you remember this: cakes made with pudding or runny add-ins such as caramel or ganache, do best in vessels with sides to contain oozing and spillage. 

Can you attempt a cake with ganache in a springform pan and hope for the best upon removal of the pan’s sides? Of course. But to be safe, you should assemble those kinds of cakes in your prettiest pottery or a Pyrex dish.

Making ahead and freezing

If its ease and flexibility haven’t persuaded you to join Team Icebox Cake, perhaps this will: not only do icebox cakes have to be made ahead - ideal for those hosts among us (um, me) who like to have as much of the meal and all of the dessert finished before her guests’ arrival - but they freeze beautifully. 

Follow the tips for wrapping and refrigerating your cake, and after 24 hours, cover it in foil and freeze for up to a month. Defrost overnight in the refrigerator before serving the next day. 

The Washington Post