01 - Combine the crushed graham crackers with melted butter in a mixing bowl until uniformly moistened. Firmly press the mixture into the base of a 9x9 inch baking dish to form an even layer.
02 - In a separate bowl, beat the cold heavy cream with powdered sugar and vanilla extract using an electric mixer or whisk until stiff peaks form.
03 - In another bowl, whisk instant vanilla pudding mix with cold whole milk for 2 minutes. Allow the pudding to stand for 5 minutes to thicken.
04 - Spread half of the whipped cream evenly over the prepared cookie base.
05 - Gently spoon the vanilla pudding on top of the whipped cream layer and smooth evenly with a spatula.
06 - Top with the remaining whipped cream, spreading to cover the pudding layer completely.
07 - Sprinkle chocolate shavings or dust with cocoa powder over the top layer if desired.
08 - Cover the dish with plastic wrap and refrigerate for at least 2 hours, or overnight, until the layers are set.
09 - Slice into portions and serve chilled.