Line an 8 x 8 inch pan with parchment paper, leaving enough overhang on top to act as handles so you can lift the bars out of the baking pan later.

Combine lemon juice, zest and condensed milk in a large mixing bowl. Whisk until lemon juice is fully incorporated. The mixture should be thick.

Add heavy cream to a separate large mixing bowl. Beat on high speed with a mixer until medium to stiff peaks form.

Using a spatula, fold the whipped heavy cream into the lemon mixture. I added the whipped heavy cream in 3 batches. You do want to be careful not to overmix. You want the heavy cream fully incorporated but you want the mixture to stay thick and airy and not become too runny.

Line the bottom of your prepared pan with graham crackers. You want to keep as many as full sheets as possible and cut the rest to fit. You want to do your best to cover the bottom of the pan with crackers with no gaps. See photo in post for reference.

Spread a thin layer of lemon cream over the layer of crackers. Place another layer of crackers over the first layer, using the same arrangement as the first layer. Pour the rest of the lemon cream filling over the second layer of crackers. Use an offset spatula to smooth and even the surface.

Place lemon bars into fridge to set (this may take a few hours). You can also leave them in the fridge overnight. Keep bars in the fridge until ready to serve. Use a sharp knife to cut them into individual bars. You can also freeze the bars about an hour before serving. This is not necessary because the bars set up nicely without any freezing, but it does make it easier to handle and serve the bars.