Nana used to whip up this 3 ingredient masterpiece right before Sunday service. I finally wrote down her method and the pan is always licked clean.

Cover and chill: Cover the dish tightly with plastic wrap or a lid and refrigerate for at least 4 hours, but ideally overnight. During this time, the whipped cream will hydrate and soften the graham crackers, turning them from crisp into a tender, cake-like texture.
Serve: When ready to serve, remove the cover and, if needed, use a knife to clean up the edges for a neat presentation in the clear glass dish. Cut into squares with a sharp knife, wiping the blade between cuts for clean layers. Use a spatula to lift out each piece, showing off the creamy, strawberry-streaked layers.
Store leftovers: Cover any remaining cake and refrigerate for up to 2–3 days. The texture will become even softer over time, which many people actually prefer; just note that the berries may release a bit more juice, adding to the “icebox” character of the dessert.
Variations & Tips
To keep the spirit of the 3-ingredient classic, think of these as gentle tweaks rather than major overhauls. For a slightly tangier profile, fold a few spoonfuls of plain Greek yogurt into part of the whipped cream for the top layer only—this gives a cheesecake-like note without changing the basic structure. If your strawberries are very sweet and in season, you can skip the powdered sugar entirely and rely on the natural fruit sweetness; conversely, for out-of-season berries, toss the slices with a teaspoon or two of sugar and let them sit 10 minutes to draw out juices and boost flavor. For a more pronounced strawberry stripe, mash a handful of the berries with a fork and swirl them lightly into one of the middle cream layers. You can also adjust the pan size: a smaller 8×8-inch glass dish will give you fewer but taller layers, while a larger dish will create thinner, more delicate layers; either way, maintain the same order of graham-cream-berries. To make ahead for a crowd, assemble the day before, chill overnight, and garnish with a fresh handful of sliced berries just before serving so the top looks vibrant. Finally, if you prefer a firmer top for cleaner slices, reserve a cup of whipped cream, chill it separately, and spread a fresh, smooth layer right before serving to refresh the appearance after a long chill.