1. Preheat oven to 350°F (175°C) and line an 8×8 or 9×9-inch square baking pan with parchment paper, leaving an overhang on two sides.

2. In a medium bowl, mix the graham cracker crumbs, melted butter, and sugar with a fork until the crumbs are evenly moistened.

3. Press the buttery crumb mixture firmly and evenly into the lined pan to form the crust.

4. Bake the crust for 10 minutes until lightly golden, then remove and let cool slightly.

5. In a clean bowl, whisk together the sweetened condensed milk, fresh lemon juice, lemon zest, and egg yolks until completely smooth.

6. Pour the lemon cream filling over the slightly cooled crust, smoothing the top with a spatula.

7. Return to the oven and bake for 12–15 minutes until the filling is set around the edges but still slightly soft in the center.

8. Let the bars cool to room temperature on a wire rack (about 30–45 minutes).

9. Transfer to the fridge and chill for at least 2 hours, ideally overnight.

10. Lift the bars out of the pan using the parchment overhang. Slice into 9 squares, wiping the knife clean between cuts. Dust with powdered sugar and extra lemon zest before serving.