SUSAN'S PERFECT LEMON BARS

Steps:

• Adjust oven rack to middle position and heat oven to 350°F.
• Lightly butter a 9 x 13 inch baking dish and line it with a sheet of parchment paper.
• Dot parchment paper with butter, then lay a second sheet of parchment crosswise over the first one, allowing the ends to extend over the top edge of the pan by about 1 inch.
• To Mix Crust in Food Processor: In a food processor, fitted with steel blade, pulse together the flour, confectioner's sugar, cornstarch and salt to mix well.
• Add 12 Tablespoons butter and process to blend (about 8 to 10 seconds), then pulse until mixture is a pale yellow color and resembles a coarse meal, (about three-1-second bursts).
• To Mix Crust By Hand: Mix flour, confectioner's sugar, cornstarch and salt together in a medium bowl.
• Freeze butter and grate it on the large holes of a box grater into the flour mixture.
• Toss butter pieces to coat.
• Rub coated butter pieces between your fingers for a minute, until flour turns pale yellow and coarse.
• Sprinkle crust mixture into parchment lined pan.
• Using both hands, firmly press mixture into an even, 1/4" layer over the entire pan bottom and about 1/2" up the sides.
• Refrigerate for about 30 minutes.
• Remove chilled crust and bake at 350°F for about 20 minutes, or until golden brown.
• Filling: Prepare filling while crust is baking.
• In a medium bowl, whisk eggs, sugar and flour.
• Stir in lemon zest, juice, milk and salt; stirring to blend well.
• Remove crust from oven, and reduce oven temperature to 325°F.
• Stir filling mixture to reblend and pour over warm crust.
• Return bars to oven and bake about 20 minutes, or until filling feels firm when lightly touched.
• Remove from oven and place pan on wire rack to cool until almost room temperature (at least 30 minutes).
• Grasp the edges of the lengthwise parchment paper (long sides of the pan) and lift the lemon bars out of the pan and onto a cutting board or counter.
• Carefully peel the paper down from the sides and using a pizza cutter or knife, slice them into serving size bars, wiping pizza cutter or knife clean between cuts as necessary.
• Sieve confectioner's sugar over bars, if desired.
• Leftover bars can be sealed in plastic wrap and refrigerated for up to 2 days.