01 - Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper, ensuring sufficient overhang for easy removal of the finished product.
02 - In a medium mixing bowl, combine the all-purpose flour, granulated sugar, and salt. Incorporate the cold, cubed unsalted butter using a pastry blender or fork until the mixture achieves a coarse crumb consistency resembling wet sand.
03 - Press the crumb mixture evenly into the bottom of the prepared baking pan to form the crust. Bake for 15 to 18 minutes, or until the crust is lightly golden. Remove from the oven and allow it to cool slightly.
04 - In a large mixing bowl, whisk the ricotta cheese until it is smooth and creamy. Add the eggs, granulated sugar, all-purpose flour, lemon zest, freshly squeezed lemon juice, vanilla extract, and a pinch of salt. Whisk vigorously until all ingredients are thoroughly combined and the filling is uniformly creamy.
05 - Carefully pour the prepared ricotta lemon filling over the partially baked crust, spreading it evenly to create a smooth surface.
06 - Return the assembled pan to the preheated oven and bake for 20 to 22 minutes. The filling should be set around the edges but still have a slight wobble in the center.
07 - Allow the bars to cool completely to room temperature on a wire rack. Once cooled, refrigerate the bars for a minimum of 2 hours to allow them to set fully before slicing.
08 - Just before serving, lightly dust the chilled ricotta lemon bars with powdered sugar for a decorative and sweet finish.