Cecilia's Linzer Sables

These are a classic. You can fill them with any jam you like, you can use any shape you like, and I imagine any combination of spices as well.

Ingredients
1.5 cups finely ground almonds, hazelnuts or walnuts (I used walnuts)
1.5 cups all-purpose flour
1.5 tsp. freshly grated cinnamon
1/4 tsp. salt
1/4 tsp. freshly ground cloves
1 large egg
2 tsp. water
1 stick unsalted butter at room temp.
1/2 cup of sugar
1/2 cup jam (I used raspberry jam)

Method
1. Whisk together the ground nuts, flour, cinnamon, salt, and cloves.
2. Using a fork, stir the egg and the water together in a small bowl.
3. Using a stand mixer with a paddle attachment beat the butter and sugar together at medium speed until smooth, scraping down the bowl as needed.
4. Add the egg mixture and beat for 1 min more.
5. Reduce the speed to low and add the dry ingredients, mixing only until they disappear into the dough. Don't work the dough much, and if need be mix the dough by hand if the mixer is unable to do it for you.
6. Divide the dough in half. Put the dough between two large sheets of plastic wrap, and press down with your hands until fairly flat. With a rolling pin, roll out the dough until it is around 1/4 inch thick. Make sure that at this time you make sure the dough is not stuck to the plastic wrap.
7. Place on a chopping board (still covered with plastic wrap) and place in the freezer for 45 min.
8. Center a rack in the oven, and preheat to 375F.
9. Line two baking sheets with parchment paper.
10. Take out the dough from the freezer. Remove the plastic wrap from 1/2.
11. Cut out the shapes, making sure that you cut a small window in 1/2 of the cookies, so that the jam can be viewed. Make sure you save the scrapes, so that you can combine them with the other half's worth of scraps, and re-freeze to make more cookies.
12. Place cut outs on the baking sheet, and bake for 11-13 min. Or until they are lightly golden and firm to the touch.
13. Repeat with the other half of the dough.
14. When cool, spread the jam on.

From Baking: From My Home to Yours, Dorie Greenspan, pp.134-6.