Preheat your oven to 350° F. Set aside two ungreased cookie sheets.
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. 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.
Notes
Pro tip: An ungreased nonstick cookie sheet works and helps the cookies stick to the pan. Do not use a silpat mat or parchment paper. The butter in the cookies will prevent them from sticking to the pan.Soft cookie dough: If you find the dough is too soft, because the shape of the cookies is not clearly defined, then add 1 to 2 tablespoons of flour. If the dough is too warm, chill it for 10 minutes.Make ahead: Dough can be refrigerated for up to three days or stored in the freezer for up to three months. Defrost in the refrigerator before bringing to room temperature.