Using a cake pan, or springform pan, set out the desired shape you'd like for the cake. Set aside.
Whip cold whipping cream until soft peaks form. Add powdered sugar, lemon juice, and 1/2 of lemon zest.
Continue whipping until stiff peaks form.
Spoon a large heap of whipped cream into bottom of cake pan. Spread evenly across bottom of pan.
On top of cream layer, add graham crackers in a single layer (Break them as needed to form to the shape of your pan - small gaps are okay.)
Repeat by adding another cream layer, then another layer of graham crackers until you are out of crackers. Finish the top with a thick layer of whipped cream and garnish with the remaining lemon zest.
Place in the fridge overnight or all day (8 hours) to set.
Serve chilled!