Preheat oven to 350°F and lightly grease a tart pan with a removeable bottom with butter or baking spray making sure to pay attention to the sides.
Combine the oats, walnuts, brown sugar and spices in a food processor. Process until finely chopped then pulse in the cubes of cold butter one by one until the mixture starts to come together.
Turn the ingredients out into the prepared tart pan and press evenly into the bottom of the pan and up the sides.
Place the crust in the refrigerator for 15 minutes.
Remove from the refrigerator, place the tart pan on a baking sheet and bake the crust for 15 minutes.
Remove from the oven, gently press down the middle if it's puffed up a bit from baking and let cool while you make the curd.
Combine the cranberries, lemon zest, ¾ cup sugar and water in a sauce pot. Bring to a simmer then lower the heat and cook for 15 minutes, stirring occasionally to help break down the cranberries.
Turn off the heat and let cool for 5 minutes then transfer the mixture to a blender and blend until smooth.
Return the mixture to the sauce pot over medium-low heat.
One by one add the remaining ingredients including the leftover 2 tablespoons of sugar to the pot whisking constantly as you go.
Once all ingredients are added to the pot, continue cooking for 10 minutes whisking constantly until the mixture has thickened.
Strain the cranberry curd over a large bowl through a fine mesh strainer using a spatula to push the curd through.
Pour the strained filling into the cooled tart crust and refrigerate for at least 3 hours until set.
Keep refrigerated until serving. Garnish with sugared cranberries or candied lemon slices.
NYT version:
FOR THE HAZELNUT CRUST:
1¼ cups/ 180 grams raw hazelnuts
1 cup/125 grams rice flour
¼ teaspoon salt
½ cup/112 grams sugar
6 tablespoons/ 100 grams softened butter, more as necessary
FOR THE CRANBERRY CURD:
12 ounces/340 grams cranberries
1 cup/225 grams sugar
Peel (orange part only) and juice of 1 orange (about ½ cup)
4 ounces/113 grams softened butter (1 stick)
2 eggs plus 2 egg yolks
Step 1
Make the crust: Heat oven to 325 degrees.
Put hazelnuts on a baking sheet and roast for 10 to 15 minutes, until skins darken and crack. Put roasted nuts in a clean towel and rub off skins. Discard skins and let nuts cool.
Step 2
In a food processor, grind nuts with half the rice flour until mixture resembles coarse cornmeal. Add remaining rice flour and salt and pulse briefly.
Step 3
Cream sugar and butter in a mixing bowl with a wooden spoon for a minute or two until pale and thick. Add nut mixture and combine until dough comes together. If it seems crumbly, add 1 to 2 tablespoons softened butter or a little cold water.
Step 4
Press dough evenly into a 10-inch tart pan; use half the dough for the sides and half for the bottom. Prick bottom with a fork and freeze for 30 minutes (or several days if desired).
Step 5
Heat oven to 350 degrees. Bake chilled tart shell about 15 minutes until lightly brown.
Cool.
Step 6
While the crust bakes and cools, make the cranberry curd: Put cranberries, sugar and orange juice and peel in a saucepan over medium heat. Simmer until cranberries have popped and softened, about 10 minutes.
Transfer to a food mill or medium mesh sieve and press cooking liquid and solids into a bowl. (Alternatively, for the most vibrant color, purée the cooked cranberry and orange mixture with an immersion blender or in a food processor or blender. Press through a fine-mesh sieve.) Whisk the butter into the warm liquid.
Step 7
Put eggs and egg yolks into a bowl and beat lightly. Slowly whisk a cup of warm cranberry liquid into the eggs to temper, then combine both and whisk together. Wipe out pot if necessary, return liquid to pot and cook over low heat until nearly bubbling and thickened, about 10 minutes. If using immediately, let cool to room temperature. If working ahead, cool to room temperature, cover with plastic wrap (press wrap against curd) and refrigerate. (Curd may be cooked up to 1 day ahead.)
Step 8
Pour cooled cranberry curd into the cooled prebaked tart shell and smooth top with a spatula. Bake at 350 degrees for 10 minutes to set curd. Cool on a rack. Store at room temperature for up to 2 days.
