Mix the fine graham cracker crumbs together with the fully melted unsalted butter inside your small bowl until it resembles wet sand.
Press the buttery crumb mixture firmly into the bottom and up the sides of your fluted tart pan using a flat glass.
Bake the empty graham shell in a preheated oven at 350°F for eight minutes until lightly toasted and fragrant.
Separate the eggs carefully and place the four yolks into your medium glass mixing bowl.
Whisk the egg yolks vigorously for one minute until they become slightly pale and smooth.
Pour the entire can of sweetened condensed milk slowly into the bowl while continuing to whisk steadily.
Stream the strained fresh lemon juice and grated lemon zest into the filling mixture causing it to thicken naturally.
Pour the smooth lemon custard filling directly over the parbaked graham crust spreading it to the edges evenly.
Bake the assembled dessert at 350°F for fifteen minutes until the borders look set but the center remains slightly wobbly.
