Perfect Lemon Bars

Place an oven rack in the middle position and preheat the oven to 350 degrees F. Line a 9X13-inch baking pan with foil or parchment paper and lightly grease the foil/parchment (optional: it helps with removing the bars after baking, but you can instead grease the pan with nonstick cooking spray).

Whisk together the flour, powdered sugar, cornstarch, and salt (this can be done in a food processor or in a large bowl by hand). Add the pieces of butter and cut the butter into the dry ingredients using a pastry blender, two knives or your fingers (taking care not to melt the butter too much - you might try freezing the butter and grating it into the dry ingredients on the large holes of a box grater) or process in the food processor for 8 to 10 seconds and then as needed until the mixture resembles coarse meal.

Sprinkle the mixture into the prepared pan and press into an even layer on the bottom. Refrigerate for 15-30 minutes. Bake until very lightly golden brown on the edges, about 15-20 minutes.

For the filling, whisk together the eggs, sugar, salt, and flour in a medium bowl and then stir in the lemon zest, juice and milk to combine.

Pour the filling onto the warm crust; reduce the oven temperature to 325 degrees and bake for about 18-20 minutes until the filling feels slightly firm to the touch. Cool the bars to room temperature, sprinkle with additional powdered sugar and cut into bars.