Linzer Cookies
from http://www.joyofbaking.com/

Also popular are cookies cut into a heart shape instead a circle with a heart cut-out.
Nice for Valentine's Day. For Christmas, use trees, snowmen or stars cutouts
- whatever small cookie cutters you have.
The Linzertorte is believed to have originated in the City of Linz, Austria in the early 1700s. Traditionally this torte consisted of a crust made with flour, ground nuts (traditionally almonds), sugar, egg yolks, spices and lemon zest that was filled with black currant preserves and then topped with a lattice crust. Linzer Cookies use the same ingredients as a Linzertorte, only presented in a different way. That is, two almond flavored cookies are sandwiched together with a layer of jam. They are so pretty, with their top cookie dusted with a thin white coating of powdered sugar and a cutout so you can see the color of the jam. When the cookies are cut in a round shape with a round cutout in the center, they are known as Linzer "Eyes" (Linzer Augen).
The Linzer Cookie batter calls for either blanched (skins off) or natural (skins on) whole almonds. (You can use an equal amount of slivered or sliced almonds.) I like to toast the almonds first to bring out their full flavor. Once cooled they need to be finely ground in your food processor. To prevent them from turning into a paste when ground, granulated white sugar is added during processing.
A few things to keep in mind when making these cookies. The baked cookies are quite crisp, but once they are filled with the jam they start to soften. So if you want to keep the cookies crisp, fill them with the jam the day of serving. Or you can fill them at least the day before serving so they become a little soft and it also allows time for the flavors to mingle. Either way they are delicious.
Cookies
1 cup (150 grams) whole almonds (blanched or natural)
2 cups (260 grams) all purpose flour
1/2 teaspoon (1 gram) ground cinnamon
1/2 teaspoon (2 grams) salt
Zest (outer yellow skin) of one small lemon
1 cup (226 grams) unsalted butter, room temperature
3/4 cup (150 grams) granulated white sugar, divided
1 teaspoon (5 grams) pure vanilla extract
2 large (40 grams) egg yolks
Topping:
1/2 cup (60 grams) confectioners' (Icing or Powdered) Sugar
1/2 cup (120 ml) Raspberry or Black Currant Jam (can use other flavored jams), well stirred
Preheat your oven to 350 degrees F (180 degrees C) with the oven rack in the center of the oven. Place the almonds on a baking sheet and bake about 8-10 minutes, or until lightly browned and fragrant. Remove from oven and once the nuts have cooled, place in a food processor, along with 1/4 cup (50 grams) white sugar, and process until finely ground.
In a separate bowl, whisk or sift together the flour, cinnamon, salt, and lemon zest.
In the bowl of your electric mixer (or with a hand mixer), beat the butter and remaining 1/2 cup (100 grams) sugar until light and fluffy (about 2-3 minutes). Beat in the vanilla extract and egg yolks. Finally, beat in the ground almonds and then the flour mixture. Divide the dough in half, cover each half with plastic wrap, and refrigerate until firm (30-60 minutes, or up to two days).
Preheat oven to 350 degrees F (180 degrees C). Line two baking sheets with parchment paper.
Remove one ball of dough from the refrigerator. On a lightly floured surface roll out the dough until it is about 1/4 inch (.5 cm) thick. Using a 3 inch (7.5 cm) cookie cutter (round, square, heart, etc.) cut out the cookies. Place the cookies about 1 inch (2.5 cm) apart on the prepared baking sheet. Use a smaller cookie cutter to cut out the centers of half of the cookies on the baking sheet. Reroll any scraps and cut out the remaining cookies. Repeat with the second ball of dough. (Note: If you find the cookies are soft, place the baking sheets with the unbaked cookies in the refrigerator for about 10 minutes to chill the dough. This will prevent the cookies from spreading and losing their shape when baked.) Bake the cookies for about 12 minutes or until lightly browned around the edges. Remove from oven and place on a wire rack to cool.
Assemble Cookies: Place the cut out cookies on a baking sheet and lightly dust the tops with powdered sugar. Spread a thin layer of jam on the bottom surface of the full cookie (top of cookie will face out). Place the cut-out cookie on top and gently sandwich them together. Using a small spoon or a piping bag, fill the cut-out with a little more jam.
The filled cookies will soften when stored. If you want the cookies to stay crisp, assemble the day of serving. The assembled cookies can be stored in the refrigerator, in an airtight container, for several days.
Makes about 26 - 3 inch (7.5 cm) Linzer Cookies.