In a large mixing bowl, combine the heavy whipping cream, vanilla extract, and powdered sugar. Use an electric mixer or a whisk to beat the mixture until soft peaks form. This will take about 3-5 minutes on medium-high speed with an electric mixer. Soft peaks are achieved when you lift the beaters out of the mixture and the peaks gently curl over.
Take a 9x13 inch pan and spread a layer of the whipped cream mixture on the bottom. You can use a spatula or the back of a spoon to spread it evenly. This layer provides a base for the rest of the ingredients.
Place a single layer of graham crackers on top of the whipped cream mixture in the pan. Break the graham crackers if needed to fit them into the pan.
Continue layering the ingredients by adding another layer of the whipped cream mixture on top of the graham crackers. Then, add a layer of sliced strawberries on top of the whipped cream.
Repeat the layering process with graham crackers, whipped cream, and strawberries until you reach the top of the pan. Make sure to end with a layer of strawberries on top for a nice presentation.
You can decorate the top of the cake with additional whipped cream, strawberries, or any other toppings you like.
Cover the pan with plastic wrap or aluminum foil and refrigerate the cake for at least 2 hours, or overnight, to allow the flavors to meld and the graham crackers to soften. Chilling also helps the cake set and makes it easier to slice and serve.
Once chilled, slice the cake into squares and serve. The cake is best served cold, so keep any leftovers refrigerated. Enjoy your delicious strawberry float cake!