Crush the graham crackers and combine them with melted butter. Press most of the mixture into a 9x13-inch dish to create a crust (reserve the rest of the crumbs for the topping). Stick the crust in the fridge.
In a large mixing bowl, pour boiling water over the lemon Jell-O and stir until fully dissolved. Add sugar (or honey), lemon juice, lemon zest, and salt, if using. Let the mixture cool to room temperature.
Once the lemon mixture is cool, whip the chilled evaporated milk on high until thick and frothy, looking for soft peaks.
Gently fold the whipped milk into the lemon mixture. Pour it over the chilled crust and top with the remaining graham cracker crumbs.
Chill in the refrigerator until fully set, which will take two to three hours.
