Preheat your oven to 350°F (175°C) and grease a 9×9 inch baking pan.

In a mixing bowl, combine the flour, cocoa powder, powdered sugar, and melted butter. Stir until you have a smooth dough and press it evenly into the bottom of your prepared baking pan.

Bake the crust in the preheated oven for 15-18 minutes until it’s lightly golden.

In another bowl, whisk together the sweetened condensed milk, fresh lemon juice, eggs, and lemon zest until thoroughly combined.

Once the crust is baked, remove it from the oven and pour the filling over the crust.

Return the pan to the oven and bake for an additional 20-25 minutes, or until the filling is set but still slightly wobbly in the center.

Allow the squares to cool completely at room temperature. Once cooled, refrigerate for at least 2 hours before cutting into squares. Sprinkle with powdered sugar before serving!