Cream together the shortening and sugar on high speed in the bowl of a stand mixer fitted with the paddle attachment (or use a large mixing bowl and electric hand mixer).
Add egg and vanilla extract; mix on medium speed to combine.
Reduce mixer speed to low; gradually incorporate the baking powder, salt and flour. *Avoid over mixing, which can cause cookies to be dry and crumbly.
Use your hands to remove the dough from the bowl. Gently press it into the dough compartment of a cookie press.
Use the cookie press to form spritz cookies, arranging them about 2 inches apart on an ungreased baking sheet. *It's very difficult to get the dough to stick to parchment-lined or greased baking sheets.
Bake in preheated 350℉ oven for 7-9 minutes, until the cookies are slightly golden brown on the edges.
Notes
Practice makes perfect! The trickiest part is getting spritz dough to stick to a baking sheet. It's very slick, so it's best to use a non-greased cookie sheet. As you release the cookie press trigger, gently pull the cookie press towards you, then upward to help the dough release.
Storing and Freezing
Baked spritz cookies will stay fresh for about 5 days in an airtight container at room temperature. For longer storage, cookies may be frozen in a freezer-safe container for up to 4 months.
Unbaked spritz cookie dough may be frozen for up to 4 months. Before inserting it into the cookie press, thaw dough in the refrigerator, then allow it to come to room temperature.