This is a fun spin on a classic Linzer cookie. Feel free to fill these buttery, nutty cookies with your favorite fruit jam. I love cranberry, especially for the holidays. Kids will love these! Dulce de leche is the new peanut butter.
Make the dulce de leche one day in advance: I like to put a small folded piece of kitchen towel on the bottom of a small, heavy-duty saucepan. Set the can directly on top and fill the saucepan with enough water to reach 2 to 3 inches over the can. Bring the pot to a full boil, then lower to a simmer. Cook for 3 to 4 hours, checking the water every 30 minutes. Don't let the water level get below the can or evaporate completely. You will destroy the pot and not have properly cooked dulce de leche. I like a darker, more caramelized cream, so I cook it for 4 hours (though 3 hours will work). Very carefully remove the hot can from the pot with tongs. Allow the can to cool for 24 hours at room temperature before opening. Store in the refrigerator for up to one week after opening.
For the cookies: Preheat the oven to 350 degrees F. Spread the hazelnuts in a single layer on a sheet pan and bake until golden brown, 8 to 10 minutes. Let cool to room temperature. Put the hazelnuts, flour, salt, cinnamon and cloves in a food processor. Pulse 8 to 10 times until the hazelnuts are finely chopped. Remove the mixture from the processor and set aside.
In a stand mixer fitted with the paddle attachment, cream the butter, sugar and orange zest until fluffy, about 2 minutes. Add the vanilla and maple extracts and the dry ingredients; mix until the dough comes together, 1 to 2 minutes. Divide the dough into two disks, flatten them, wrap in plastic and chill for 1 hour.
Working with one disk of dough at a time, roll the dough between two sheets of parchment. Roll out to an 11- to- 12-inch round. The dough should be slightly thinner than 1/4 inch. Chill that piece and repeat with the second disk. Chill both rounds of dough until very firm (the freezer can help if time is important).
Line two sheet pans with parchment; set aside. From one round of dough, cut out twenty-eight 2 1/2-inch cookies. I like to use a square cutter just to mix it up from the traditional round cookie. Cut out cookies from the second round of dough-these will become the tops of the cookies. You will need to cut out a small 1-inch round center hole from the second set of cookies, which will allow you to see the filling of the finished cookie. Bake the punched holes for snacking on.
Once all the cookies are cut, arrange on the prepared pans and chill until cold or overnight.
Preheat the oven to 350 degrees F. Bake the cookies until they're light golden brown, 16 to 18 minutes. Remove from the oven and let cool to room temperature.
Top the bottom cookies with the dulce de leche or your favorite fruit jam or jelly. I love cranberry-orange jam. Sift confectioners' sugar on the cookie tops while on the sheet pan, then place on top of the filled bottom cookies; light press together.
The filled cookies should be eaten the same day. Unfilled cookies will sit very well for 4 to 5 days wrapped airtight at room temperature.