Preheat oven to 350 degrees F. Line a muffin tin with parchment paper liners.

Place the graham crackers into a food processor and pulse until they are fine crumbs. Transfer to a bowl and stir in sugar, butter, and salt until the crumbs are fully moistened.

Place 1 tablespoon of moistened crumbs into the bottom of each muffin liner and press down firmly with the back of a spoon to form a crust.

Bake for 5-6 minutes until the crusts are golden brown. Allow the crusts to cool at room temperature while you make the filling.

Whisk together the sweetened condensed milk, lime juice, zest, and egg yolks in a large bowl.

Spoon two tablespoons of the filling into each of the cooled crusts.

Bake for 9-11 minutes until the middle of the pies are only slightly jiggly. Cool for 10 minutes at room temperature before refrigerating for at least 2 hours or overnight.

When ready to serve, remove from the muffin liners and garnish with fresh whipped cream or lime zest.