01 -
Line a 9x13-inch baking pan with parchment paper, creating overhanging edges on the two long sides to form a sling. Coat the paper and exposed sides with cooking spray.
02 -
In a food processor, pulse walnut pieces until coarsely ground (about 15 pulses). Add flour, powdered sugar, cinnamon, and salt, then pulse until finely ground (about 10 pulses). Scatter butter pieces over the mixture and pulse until moist clumps form (20-25 pulses).
03 -
Transfer the mixture into the prepared baking dish and press evenly using your hands or the bottom of a floured measuring cup. Refrigerate for at least 30 minutes.
04 -
Preheat oven to 350°F with rack in middle position. Bake the chilled crust until edges begin to brown, 20-25 minutes. Meanwhile, prepare the cranberry curd.
05 -
Combine cranberries and water in a medium saucepan over medium-high heat. Bring to a boil and cook, stirring occasionally, until all cranberries burst and become soft, about 5 minutes. Set a fine-mesh strainer over a large bowl.
06 -
Pour the cranberry mixture into the strainer and press through using a spatula until only pulp remains. Set purée aside to cool to room temperature, about 10 minutes. Discard pulp and clean the strainer and saucepan for reuse.
07 -
Whisk sugar, eggs, egg yolks, lemon juice, and salt into the cooled cranberry purée until smooth.
08 -
Return the cranberry mixture to the saucepan over medium heat. Stir continuously, scraping bottom and corners, until it simmers, thickens slightly, coats the back of a spoon, and reaches approximately 150°F, about 5-11 minutes.
09 -
Remove from heat, add butter all at once, and stir until completely melted. Strain the curd through a fine-mesh strainer into a clean bowl to remove any cooked egg pieces.
10 -
Pour the warm cranberry curd onto the baked crust and spread into an even layer. Bake until the curd is set but still jiggles slightly in the center, 10-15 minutes.
11 -
Place the pan on a wire rack and cool for 1 hour. Refrigerate until completely chilled, at least 2 hours and up to 1 day.
12 -
Run a thin knife around the edges of the pan. Use the parchment paper handles to lift the slab onto a cutting board. Trim edges if desired and cut into 24 pieces. Dust with powdered sugar and garnish each square with candied citrus zest if desired.