In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth.
Gradually add the powdered sugar and vanilla extract, mixing until well combined.
Gently fold in the whipped topping until the mixture is light and fluffy.
In a separate bowl, combine the strawberries, blueberries, and lemon juice. Toss gently to coat the berries.
In a large serving bowl, layer half of the cream cheese mixture, followed by half of the berry mixture, and half of the crushed graham crackers.
Repeat the layers with the remaining cream cheese mixture, berries, and graham crackers.
Cover and refrigerate for at least 1 hour before serving to allow the flavors to meld.