Step 1

Heat the oven to 350ºF. Lightly coat an 8-inch square baking pan (at least 2 inches high) with cooking spray. Line the bottom and sides with 2 sheets of parchment paper positioned perpendicular to each other so that there is parchment overhanging on all 4 sides. Lightly spray between the sheets if needed to keep the paper in place.

Step 2

Beat 1 stick room-temperature unsalted butter, 1/4 cup granulated sugar, and 1/2 teaspoon kosher salt with the paddle attachment in a stand mixer on medium speed until creamy, about 2 minutes. Scrape down the sides of the bowl with a flexible spatula.

Step 3

Beat in 1 cup all-purpose flour on the lowest speed just until a crumbly dough forms, about 30 seconds. Transfer to the baking pan and use your hands or the bottom of a flat measuring cup dusted with flour to press it into an even layer.

Step 4

Bake until the crust is golden-brown around the edges, 20 to 25 minutes. A few minutes before the crust is ready, make the lemon filling.

Step 5

Whisk 4 room-temperature large eggs, 1 1/2 cups granulated sugar, 1 1/2 teaspoons finely grated lemon zest, 1/2 cup lemon juice, and 1/2 teaspoon kosher salt together in a large bowl until smooth. Sift 1/2 cup all-purpose flour through a fine-mesh strainer over the mixture and whisk until smooth and combined.

Step 6

When the crust is ready, immediately dollop and spread 1 cup whole berry cranberry sauce onto the crust in an even layer while it is still hot. Very slowly pour the lemon filling (rewhisk first if needed) over the back of a large spoon evenly over the cranberry layer, being careful not to disturb the cranberry layer too much (a few pieces of cranberry may float; that’s OK).

Step 7

Bake until the filling is set and does not jiggle anymore, 30 to 35 minutes. Place the pan on a wire rack and let cool for 1 hour. Refrigerate until the lemon layer is set, at least 4 hours or up to overnight.

Step 8

Grasping the excess parchment, lift the slab out of the baking pan and place on a cutting board. Cut into 16 pieces, dipping the knife in hot water and wiping it dry between each cut for the cleanest-looking pieces if desired. Right before serving, place some powdered sugar in a fine-mesh strainer and generously dust over the lemon bars in an even layer.