Prep the berries: Rinse and pat dry thoroughly. Slice strawberries. Set aside.
Make the lemon cream base: In a large bowl, beat the softened cream cheese with powdered sugar, vanilla, lemon zest, lemon juice, and a pinch of salt until smooth and fluffy.
Whip the cream: In a separate cold bowl, whip the heavy cream to stiff peaks.
Fold together: Gently fold the whipped cream into the lemon-cream cheese mixture until no streaks remain.
Taste and adjust sweetness if needed.
Layer the pan: Spread a thin layer of lemon cream on the bottom of an 8x8 or 9x9-inch dish. Add a single layer of graham crackers, breaking pieces to fit snugly.
Add berries: Spread a generous layer of the lemon cream over the crackers, then scatter an even layer of mixed berries on top.
Repeat layers: Continue with graham crackers, lemon cream, then berries. Aim for 3 layers, finishing with lemon cream on top.
Chill: Cover and refrigerate for at least 4 hours, preferably overnight, so the crackers soften and the flavors meld.
Garnish and serve: Top with extra berries, a little lemon zest, and mint if you like.
Slice and serve chilled.