Make the dough

1. Preheat the oven to 350 F (180 C).  Spread out the hazelnuts on a sheet tray and then toast the nuts for 8 minutes just until you begin to smell them.  Set the nuts aside to cool.
2. Beat the butter, powdered sugar and lemon sugar (if using) with a mixer until smooth.
3. Add in the egg yolk and vanilla and beat until smooth.
4. Grind the cooled nuts in a food processor

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   .
5. Mix the nuts with the flour, cinnamon, cloves, and salt.
6. Add the flour to the butter mixture and mix just until the flour disappears and the dough comes together.
7. Gather the dough together in the middle of a piece of plastic.  Press on the dough to make a small compact disc. 

Rolling the cookies

1. Divide the dough in half.
2. Sprinkle one sheet of parchment

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   paper with flour.  Place half of the dough on top of the floured parchment

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   , sprinkling the dough with a little more flour.  Place a second piece of parchment

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   over the dough.
3. Slide the parchment

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   sandwich down to the edge of the counter, anchoring the edge of the paper with your hip.  Roll the dough between the parchment

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   until it is 1/8” thick.
4. Repeat with two more pieces of parchment

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   and the second half of the dough.  Slide the rolled out dough onto a sheet tray and chill in the freezer until the parchment

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   peels away easily from the dough.  This will take about 15 minutes.
5. After 15 minutes, pull out one of the dough packages from the freezer.
6. Peel off the top piece of parchment

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   and use it to line a sheet tray for baking the cookies.  Use a 2 and 1/2″ round cutter to cut rounds of dough as close together as possible with a round cutter or a glass.  Place the rounds onto parchment

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   lined sheets leaving about 1” of space around each cookie.
7. Cut out the middle of every other cookie round with a smaller cookie cutter like a heart, star, flower, etc.  If you don’t have any small cookie cutters,use what you have.  The bottom of a cake decorating tip can make a good sized hole.  Cut the second half of the dough the same way.  You should be able to bake two sheets of cookies at the same time.
8. Bake the cookies for 7-8 minutes rotating the sheet trays 180 degrees around and switching them from top to bottom (or bottom to top) halfway through baking.
9. Reroll your dough scraps, chilling the dough as necessary so that you can easily peel the cut cookies off the parchment

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   .  You can also bake the centers of the cookies if you don’t want to reroll as many cookies.

Finishing the cookies

1. To finish the cookies, scoop the jam into a small bowl.  Stir the jam vigorously for a few seconds to loosen the jam.  If the jam feels too thick and hard to spread, microwave it for a few seconds.
2. Spread the bottom of each cookie with about a teaspoon of jam.  Top the jam with the cookie tops (the ones with the middles cut out of them).  If you’d like, sprinkle them with a little powdered sugar for an extra festive touch.
3. Without the filling, Linzers will keep in an airtight container at room temperature for about a week.  Do not fill them until you’re ready to serve them as the jam will soften the cookies.  Filled cookies should be eaten within a day or two.