Instructions:
Cut strawberries into thin slices. Set aside.
Whipped Cream:
Whip heavy whipping cream in a bowl with a mixer until it holds soft peaks. Add powdered sugar and vanilla extract, and whip to combine until stiff peaks form. Do not over mix. Set aside.
Cake Assembly:
1st Layer. To start assembling the cake, arrange 1st layer of 6 graham crackers by spreading a thin layer of whipped cream on the bottom of each cracker and place them with the cream side down so that they don’t slide while making the cake.
Lightly cover the top of the graham crackers with more whipped cream, and then a single layer of strawberries and blueberries. Spread a thin layer of whipped cream on top of the berries.
Add 2nd layer of 6 graham crackers (no need to add whipped cream to the bottom of the cracker now – it’s only done for the very first layer), whipped cream, berries and more cream.
Add 3rd layer of 6 graham crackers, whipped cream, berries and more cream.
Finally add 4th layer of graham crackers. Spread the last of the whipped cream over the top and flatten it slightly with a spatula. Add remaining strawberries and blueberries.
Refrigerate or freeze:
Refrigerate for at least 4 hours or overnight until the graham crackers have softened.
You can also freeze it for one hour.