Zest your limes (make sure you only take the green and don't go down to the white, that part is bitter). It took 5 small limes for me to get a heaping tablespoon.
Juice those same limes you just zested to get a 1/2 cup of lime juice. That took 6 small limes for me.
In a medium bowl, whisk the egg yolks and lime zest together for about 2 minutes. The mixture should be yellow-green and frothy.
Whisk in the condensed milk until smooth then whisk in the lime juice and pinch of salt until fully incorporated. Cover and set aside.
Preheat your oven to 325 degrees.
Break up your graham crackers and put into the food processor. Pulse until you have fine crumbs.
Pour in the melted butter, sugar, and pinch of salt. Pulse about 6 times until it comes together and your mixture looks like wet sand.
Pour the graham cracker mixture into a 9" pie plate and press into an even layer. I used the bottom of a measuring cup to help press it down evenly.
Bake the crust for 13-16 minutes then remove.
Pour your lime filling into the warm crust and bake for 15-18 minutes.
Remove from the oven and let cool for about an hour before you move it to the fridge. Once it's cool, let it chill in the refrigerator for 2-3 hours to fully set. I covered mine and let it sit over night.
When ready to serve, I used a can of Redi-Whip to decorate/garnish the outer edge of the crust.