In a large mixing bowl, whip the heavy cream, powdered sugar, and vanilla extract together until stiff peaks form.
In a 9x13 inch baking dish, spread a thin layer of strawberry jam on the bottom.
Layer graham crackers over the jam, covering the bottom completely.
Spread half of the whipped cream mixture over the graham crackers, then add a layer of sliced strawberries on top.
Repeat the layers with more graham crackers, the remaining whipped cream, and the rest of the strawberries.
Finish with a final layer of graham crackers and spread the remaining strawberry jam on top.
Cover the dish with plastic wrap and refrigerate for at least 4 hours or overnight to allow the flavors to meld and the cake to set.
Slice and serve chilled.