Preheat your oven to 175°C (350°F). Line a 9x13 inch baking dish with parchment paper, leaving some overhang for easy removal.
In a mixing bowl, combine the flour and powdered sugar. Add the cold butter, cut into small pieces, and use a pastry cutter or forks to blend until the mixture resembles coarse crumbs.
Press this crumbly mixture evenly into the bottom of the prepared dish. Use the back of a spoon or your fingers to smooth it out. Bake for 18-20 minutes until lightly golden and fragrant.
While the crust bakes, whisk together the eggs, granulated sugar, lemon juice, and lemon zest in a bowl until smooth. The mixture should be glossy and slightly frothy, with a bright yellow color.
Once the crust is baked and golden, carefully pour the lemon filling over it, spreading evenly with a spatula or spoon.
Return the dish to the oven and bake for another 20-22 minutes, until the filling is just set but still slightly jiggly in the center and the top is glossy.
Remove from the oven and let the lemon bars cool completely in the pan on a wire rack, about 1-2 hours. They should develop a firm, glossy top and a tender crust.
Once cooled, dust the top generously with sifted powdered sugar for a delicate finish. Use a sharp knife to cut into neat squares, wiping the blade clean between cuts.
Serve the lemon bars at room temperature or chilled, enjoying the bright citrus flavor and tender, crumbly texture with each bite.
