Preheat your oven to 350° F. Grease two baking sheets and set aside.¹
In the bowl of your electric mixer, or with a hand mixer and a large bowl, beat the butter and sugar until fluffy (2-3 minutes). Add the egg yolks and vanilla extract. Beat until incorporated. Scrape down the sides of the bowl as needed.
With the mixer on low, slowly add the flour and salt. Beat until incorporated, about 1 minute.
Scrape some of the dough into your cookie press that has been fitted with a decorative disc (follow manufacturer's instructions). Hold the cookie press perpendicular to your baking sheet, and press out the cookies.² Continue to press out the cookies, spacing about 2 inches apart. Decorate with desired sprinkles.
Bake cookies for 10 to 12 minutes or just until the edges of the cookies are turning golden. Gently transfer the cookies to a wire rack to cool completely. Store cookies in a covered container for up to a week.³
For this recipe I suggest greasing cookie sheets as opposed to lining them with parchment paper. When I used parchment paper, the pressed cookie dough wouldn't release from the cookie press.
If you find the dough is too soft, because the shape of the cookies is not clearly defined, then chill the dough.
Dough can be refrigerated for up to three days or stored in the freezer for up to three months. Allow frozen dough to defrost in the refrigerator then bring it to room temperature.