Pistachio Linzer Cookies

Grind the pistachios in a grinder, or use a food processor.

Sift the flour, powdered sugar, and ground pistachios into a bowl. Add the egg, salt, grated lemon zest, and butter cut into smaller pieces. You can mix everything by hand, or use the K-beater attachment on a stand mixer. As soon as the ingredients start to combine, stop the mixer, turn the dough out onto a work surface, and knead by hand. If the dough doesn't come together, add a little water, but carefully, so it's not too much. Work quickly to prevent the butter from melting. Spread the dough several times with the heel of your hand against the work surface; this will perfectly combine the ingredients. Form a ball or a log, wrap it in plastic wrap, and refrigerate overnight (or for at least 4 hours).

Divide the dough in half, generously dust with flour, and roll out to a 2 - 4 mm thick sheet. For small shapes, the thickness can be 2 mm; for larger shapes, 3 - 4 mm is ideal. Dust with flour regularly while rolling.