Preheat the oven to 350F. Line an 8x8 pan with foil or parchment paper. Leave an overhang on the sides for easy removal once cooled.
In a small bowl combine the graham cracker crumbs, salt, sugar, and melted butter. Mix until fully combined. The mixture should be the texture of wet sand.
Firmly press the crumbs in the bottom of the pan.
Bake the crust for 8-10 minutes or until golden brown. Remove the pan from the oven and allow to cool completely. Leave oven on.
For Filling:
In a medium bowl combine the yolks and zest. Beat with a hand mixer until thickened, about 3-5 minutes.
Mixing constantly, add the sweetened condensed milk in a steady stream until fully combined.
Add the lemon juice and mix until fully combined.
Pour the filling over the crust. Bake for 10-12 minutes or until the filling is set and no longer jiggly.
Remove from oven and allow to cool completely. Place in the fridge for 3 hours or until thoroughly chilled.
For Whipped Cream:
In a medium bowl beat the cream and sugar to stiff peaks, be careful not to overwhip.
Spread or pipe the whipped cream onto the cooled bars.
Notes
Store in an air tight container.Make sure the crust is completely cool before pouring the filling mixture.Use fresh lemon juice only.