Preheat oven to 350 degrees. Line a 9x9-inch pan with aluminum foil or parchment paper, set aside.
In a food processor or in a large ziploc bag with a rolling pin, crush the graham crackers until fine crumbs form.
In a medium mixing bowl, combine the crumbs, sugar, salt and butter, mix to combine. Press the crumbs evenly into the bottom of the lined pan. Place in the oven and bake for 10 minutes.
Meanwhile, in a large mixing bowl with a hand mixer or the bowl of a stand mixer, beat the cream cheese until smooth and creamy. Add the condensed milk and mix until combined.
Then, add the egg yolks one at a time, mixing well after each addition followed by the lime zest, juice and vanilla extract, mix until combined.
Pour the filling over the hot, baked crust. Return to the oven and bake for 15-18 minutes or until set. The top should not brown. Remove from the oven and chill in the refrigerator for 2-4 hours before serving. I prefer dense, cold bars, so I generally give them the full 4 hours, however, the pictures taken above were shot after 2 hours.
Cut and serve, store in an airtight container in the refrigerator for up to 5 days.