Prep the strawberries: Slice the berries. In a bowl, toss with lemon juice if using. Set aside. If using jam, warm it slightly and thin with a teaspoon of water for drizzling.

Make the whipped cream: In a chilled bowl, beat the cold heavy cream, powdered sugar, vanilla, and salt until medium-stiff peaks form. Don’t overbeat—stop when it’s smooth and holds peaks.

Start layering: Spread a thin layer of whipped cream on the bottom of a 9x13-inch dish. This helps the crackers stay in place.

First layer of crackers: Arrange a single layer of graham crackers over the cream, breaking pieces as needed to cover the bottom.

Add cream and berries: Spread about 1/3 of the whipped cream over the crackers. Top with an even layer of sliced strawberries. Drizzle lightly with the jam mixture if using.

Repeat layers: Add another layer of crackers, then cream, then strawberries. Repeat for a third time, finishing with a final layer of cream on top. Reserve a handful of berries for garnish.

Chill: Cover tightly and refrigerate for at least 6 hours, ideally overnight. This is when the magic happens—the crackers soften into a cake-like texture.

Garnish and serve: Right before serving, top with the reserved berries. Slice with a sharp knife and use a spatula to lift clean squares.