Sift together the all-purpose flour, salt, baking soda, and cream of tartar in a medium bowl—sifting removes lumps and helps distribute the leavening agents evenly for consistent texture. Set this dry mixture aside. Preheat your oven to 375°F and line baking sheets with parchment paper. Bring your eggs to room temperature by letting them sit on the counter for about 10 minutes; this helps them incorporate more smoothly into the butter mixture, creating a fluffier dough.

In a large mixing bowl, combine the softened salted butter and shortening, then beat on medium-high speed for about 2 minutes until light and creamy. This step is crucial—the combination of butter and shortening creates that classic crispy texture spritz cookies are known for, while the creaming process incorporates air that helps with lift. Gradually add the powdered sugar and granulated sugar, continuing to beat for another 2-3 minutes until the mixture is light, fluffy, and pale in color.

Add the room-temperature eggs one at a time to the creamed mixture, beating well after each addition to ensure they're fully incorporated. Pour in the vanilla extract and mix until everything is combined into a smooth, homogeneous base. I like to scrape down the bowl between additions to make sure no streaks of egg white remain—this ensures even mixing and consistent cookie texture throughout the batch.

Add the dry ingredient mixture from Step 1 to the wet base in two additions, mixing on low speed after each addition just until the flour is incorporated. Don't overmix—overworking the dough at this stage can develop gluten and make the cookies tough. Mix until you have a smooth, uniform dough with no visible streaks of flour.

Transfer the dough to the refrigerator and chill for at least 30 minutes, though you can chill it for up to 2 hours if needed. Chilling makes the dough firmer and easier to work with in your cookie press, preventing it from spreading too much during baking. The cold dough also helps maintain crisp edges while keeping the centers tender.

Remove the dough from the refrigerator and load it into a cookie press fitted with your desired shape plate. Press cookies onto the prepared baking sheets, spacing them about 1.5 inches apart. If your dough becomes too warm and difficult to press, return it to the refrigerator for 5-10 minutes. The pressed shape from the cookie gun is what makes spritz cookies distinctive, so take your time to create clean, uniform impressions.

Bake the cookies at 375°F for 8-12 minutes, watching carefully toward the end—they should be set but still pale, with just the slightest golden tint on the edges. Overbaking will make them hard rather than crisp. Let the cookies cool on the baking sheet for 2 minutes, then transfer them to a cooling rack to cool completely. I find that this brief rest on the hot pan helps them firm up just enough to handle without breaking, while the cooling rack prevents them from getting soggy on the bottom.