Prepare the base (10 minutes):
Preheat oven to 180°C. Grease a 20cm square baking dish with melted butter.
Puree the graham crackers until fine crumbs are obtained in a food processor or blender.
Alternatively, place the graham crackers in a resealable bag and crush them with a rolling pin.
In a large bowl, combine the graham cracker crumbs, melted butter and sugar. Mix until well combined and the crumbs are evenly moistened.
Press the crumb mixture firmly into the base of the prepared baking dish.
Use a spatula or the back of a measuring cup to ensure the base is evenly filled.
Bake the base for 8-12 minutes or until lightly golden brown.
Remove the pan from the oven and allow the base to cool completely on a wire rack before adding the filling.
Lemon Filling (10 minutes):
In a large bowl, whisk together the egg yolks and sweetened condensed milk until smooth and well combined.
Stir in the freshly squeezed lemon juice and whisk until fully combined. The filling will be slightly thicker at this point.
Bake and chill (30 minutes + 1 hour):
Pour the lemon filling over the cooled base and spread it evenly around the edges.
Bake the lemon wedges for 15 minutes or until the filling is set. The edges should be lightly golden brown and the center should just set (it will continue to set as it cools).
Remove the pan from the oven and let the lemon wedges cool completely on a wire rack at room temperature.
Serve and enjoy! Once the filling has cooled, refrigerate the lemon wedges for at least an hour or until the filling is completely cold and firm. Cut the lemon bars into pieces and serve cold. Enjoy them as is or with whipped cream for an extra delicious treat.