Lemon Bars for a Crowd

 Lemon Bars for a Crowd 

aka. Cookie sheet Lemon Bars 18"x13" 

 A large half-sheet baking pan (18"x13") is perfect for making a large batch of these perfect, sweet, & tangy lemon bars. 

Ingredients 

CRUST 
2 2/3 cup all purpose flour 
1 cup powdered sugar, plus extra for dusting tops of lemon bars 
1/3 cup cornstarch 
3/4 teaspoon salt (omit if using salted butter) 
1 cup, plus 2 Tablespoons butter, cut into pieces, room temperature 

FILLING 
6 large eggs 
2 cups granulated sugar 
4 1/2 TBSP all purpose flour 
3 teaspoons grated lemon zest (about 2 lemons) 
1 cup freshly squeezed lemon juice (about 4-5 lemons) 
1/2 cup milk (whole milk is best) 
Pinch (about 1/8 teaspoon) salt 

METHOD

Preheat oven to 350f. Lightly grease a 13"x18" baking sheet pan and line it with parchment.

Mix together flour, powdered sugar, cornstarch (and salt, if using Unsalted butter) in a large bowl or food processor. 

Add the room temperature butter and using a pastry blender, 2 forks or food processor, mix till mixture is fine and crumbly. 

Sprinkle the mixture into the prepared baking sheet. Use a rubber or offset spatula to make an even layer and press firmly with the spatula or a sturdy drinking glass on the bottom and 1/2" up the sides of the pan. 

Refrigerate the crust for 30 minutes. Bake the crust for 20 minutes. 

Prepare the filling. Whisk the eggs, sugar, salt and flour in a medium bowl or electric mixer with whisk attachment. Add lemon zest, juice and milk. Beat for 3 minutes, until slightly thickened. 

Pour the filling into the WARM crust and REDUCE the oven temperature to 325°F. 8. Bake for 18-20 minutes, or till the filling feels slightly firm to the touch. 

Cool the bars completely on a wire cooling rack, about 30 minutes. When bars have cooled, sprinkle tops of bars with powdered sugar and cut into bars. 
Serve immediately!