Line baking sheets with parchment paper or silpat mats. Set aside.
In a medium sized mixing bowl or stand mixer, beat together butter, sugar, and egg yolk until smooth. Add vanilla and optional almond extract and mix until incorporated. Add flour and salt and mix until combined.
Transfer dough to piping bag fitted with an open star piping tip (I used Ateco #826). Pipe small rings of dough, about 1 1/2" in diameter, spacing them 1" apart on cookie sheets. If dough has a peak when you pull up with piping bag, just push down with your finger to connect the dough.
Chill piped cookie dough in fridge for 15-30 minutes. Preheat oven to 350 degrees while cookie dough is chilling.
Bake cookies, one pan at a time, for 11-13 minutes at 350 degrees until barely turning golden on the edges. Remove from oven and allow to cool completely on baking sheets.