For the curd:
For the hazelnut cookies:
Combine the cranberries, water, and orange juice in a medium saucepan over medium heat. Cover and let cook, stirring occasionally, until the cranberries burst, about 30-35 minutes. Press through a fine sieve, scraping the bottom of the sieve to get as much pulp as possible (you should have about 1¾ cups). Discard the solids.
In a medium saucepan, combine the pulp with the butter, sugar, and salt. Cook over medium heat, stirring, until the butter is melted and the sugar is dissolved, about 7 minutes. In a bowl or large liquid measuring cup, whisk together the egg yolks and whole egg. Then whisk in cranberry mixture, 2-3 tablespoons at a time, stirring constantly to prevent the eggs from curdling. Return the egg-cranberry mixture to pan and cook over low heat, stirring constantly, until the mixture is thickened and coats the back of a wooden spoon, about 6-8 minutes. Remove from the heat and strain the mixture through a sieve into a bowl. Press plastic wrap directly on surface of curd to cover, and refrigerate until cold, about 30-60 minutes. (This will be more curd than you need to fill the cookies, but it is great stuff to have around for many things. Spreading on a biscuit or muffin, stirring into yogurt, topping ice cream, pancakes, waffles, etc. So many possibilities!)
Meanwhile, to make the cookies, preheat the oven to 350˚ F. Place the hazelnuts in the bowl of a food processor. Pulse until finely ground to the texture of coarse sand. Add in the butter, salt, brown sugar and flour to the food processor. Pulse until the mixture forms a cohesive dough.* Form the dough into a ball and wrap in plastic wrap. Chill at least 1 hour before proceeding.
Take a small portion of dough (about 1 tablespoons) and press into the well of a mini muffin pan, creating a well with your thumb. Repeat with the remaining dough. 2 teaspoons dough into a ball and press into tart cup, creating a well for the filling with your thumb. Repeat with remaining dough mixture. Bake the cookie shells 15-20 minutes or until golden brown and just set. If the center has puffed up some during baking, press down gently. Let cool completely in the pans before carefully removing to a serving platter.
Fill each cookie shell with a small spoonful of the cranberry curd and garnish with a few sugared cranberries. Serve within 4-6 hours.**
*The dough can be mixed in a regular mixer, but the hazelnuts need to be pretty finely ground for this recipe so a food processor or other grinding mechanism is necessary.
**These are best within a few hours of assembly, but all the components can be made in advance.