Preheat the oven to 350F. Grease an 8-inch square baking pan with non-stick cooking spray. Set aside.

Prepare the graham crackers crumbs by pulsing the crackers in a food processor. The mixture should be sandy. Then, add the melted butter, sugar, and salt. Pulse to combine well.

Transfer the graham cracker mixture to the prepared baking pan. Press the mixture firmly to the bottom using the back of a spoon or the back of a measuring cup.

Bake for 10 minutes or until lightly browned. Set aside. Let the graham cracker crust cool for 20-30 minutes.

In a mixing bowl, combine condensed milk, egg yolks, lemon juice, and lemon zest using an electric mixer. Beat until fully combined and pour into the cooled graham crackers crust.

Bake for 10-12 minutes more or until the creamy lemon filling sets. Remove from the oven. Let it cool to room temperature on the counter. Then, refrigerate for 1 hour before serving.

Slice and serve with whipped cream or powdered sugar.