In a medium bowl, combine sliced strawberries with 1/4 cup of powdered sugar. Mix gently and set aside for about 30 minutes to allow the strawberries to release their juices.
In a separate mixing bowl, whip the heavy cream with the remaining 1/4 cup of powdered sugar, vanilla extract, and a pinch of salt until soft peaks form. Be careful not to overwhip; it should be light and fluffy.
Add the Greek yogurt and lemon zest to the whipped cream mixture and gently fold until well combined.
Take a 9x9 inch square baking dish or a similar-sized dish. Lay a single layer of graham crackers at the bottom of the dish, breaking them if necessary to fit.
Spread a third of the yogurt and whipped cream mixture over the graham crackers, smoothing it into an even layer.
Spoon half of the macerated strawberries over the cream mixture, spreading them out evenly.
Repeat the layering process with another layer of graham crackers, another third of the cream mixture, and the rest of the strawberries.
Top with a final layer of graham crackers and then the last of the whipped cream mixture. Smooth the top and refrigerate for at least 4 hours, or overnight if possible, to let the flavors meld and the crackers soften.
Before serving, garnish with extra fresh strawberries on top for decoration if desired.