1/2 pound whole shelled hazelnuts
1 cup cake flour, plus more for dusting
1/2 pound unsalted butter, room temperature, cut into chunks
1 cup sugar
1/2 teaspoon ground cinnamon
1/4 teaspoon ground cloves
1 teaspoon lemon zest
1 1/2 cups raspberry jam
Powdered sugar, for decorating
Preheat oven to 400 degrees F. Position the rack in the middle of the oven.
Spread hazelnuts in a single layer on a baking sheet and toast them in the oven until golden, about 10 minutes. Turn oven off since you will not need it on again for at least 45 minutes. Empty nuts onto a folded towel, enclosing them between the folds, and rub them to remove their skins. Transfer the nuts to a strainer and carefully discard the skins. Allow nuts to cool to room temperature.
Put the hazelnuts in a food processor fitted with the stainless-steel blade and pulse a few times. Add cake flour and process until the nuts are finely ground. Set aside.
In a mixer fitted with the paddle attachment, beat butter, sugar, cinnamon, cloves, and lemon zest on medium speed until light and creamy. Turn the mixer off and scrape down the sides of the bowl. Over medium speed, add the egg and continue mixing for 1 more minute. Reduce the speed to low, add the hazelnut-flour mixture, and continue mixing until well blended into a smooth dough.
Divide the dough into 2 portions, with 1 portion about 8 ounces or 1/3 of the dough. Transfer to a medium pastry bag fitted with a number 1 plain tip and set aside. With the remaining 2/3 of the dough (about 20 ounces), form into a 1-inch flat disc. Wrap in plastic wrap and refrigerate for at least 30 minutes.
Preheat oven to 350 degrees F.
With a marking pen, trace a 16 by 13-inch rectangle shape on parchment paper. Place paper, marked side down, onto a baking sheet. With the reserved dough in the pastry bag, pipe straight parallel lines, about 1-inch apart, inside the marked rectangle. Then pipe a second set of parallel lines at a 45 degree angle to the first set of lines to make a trellis shape. Refrigerate until needed (dough should be well chilled before using).
With more cake flour, lightly dust a pastry board or work surface with flour. With a rolling pin, roll out the dough to a rectangular shape, about 15 by 12 inches by 1/4-inch thick. Transfer dough to a parchment lined baking sheet and trim any excess dough to make an even rectangle. Bake for 20 minutes, or until dough starts to color. Remove baking sheet from the oven and transfer to a rack. Leave oven on. Allow dough to cool for at least 10 minutes.
Spread raspberry jam over the entire surface of the cooled dough. Carefully place the refrigerated trellis-shaped dough over the jam. Return to the oven and bake for 20 minutes, or until crust is golden in color. Allow to cool completely before cutting. Trim edges and then cut into 3 by 1-inch bars. Lightly dust bars with powdered sugar.