• Line a 9 x 5-inch loaf pan (or size you have) with plastic wrap, leaving excess to drape over the edge so the icebox cake can be easily removed from the pan after freezing. Then zest the lemon and set it aside.
• Pour cold heavy whipping cream into a bowl and add the powdered sugar and juice from one lemon. Using the whisk attachment on a handheld mixer (or in a stand mixer with the whisk attachment), beat the cream until stiff peaks form so that when you pull out the whisk, the peaks continue to stand. Fold in the lemon zest and vanilla.

Assemble the Icebox Cake

• Into the bottom of the prepared loaf pan (or square pan), create a layer of graham crackers, breaking as needed to cover the entire bottom. On my loaf pan, it took 3 1/2 sheets of graham crackers.
• Spread a layer of whipping cream over the top, followed by a layer of berries. In my pan, each layer of whipping cream was about 1 to 1 ½ inches high.
• Repeat this process until you reach the top of the pan. I like to have at least 3 layers.

Freeze Icebox Cake

• Cover the cake with plastic wrap and freeze for at least 4 hours or even overnight.
• When ready to serve, remove the cake from the pan using the plastic wrap "handles" and peel back the plastic wrap. Top with fresh berries, additional lemon zest, and mint leaves if desired. Let the cake thaw a bit before slicing and serving.