Preheat the oven to 375°F (190°C) and line two baking sheets with parchment paper.

In a large bowl, cream together softened butter and granulated sugar until light and fluffy.

Add egg yolks one at a time, mixing well after each addition, then stir in vanilla extract.

In another bowl, whisk together flour, baking powder, and salt. Gradually mix the dry ingredients into the wet mixture until just combined.

Fill a cookie press with dough and pipe onto prepared baking sheets, leaving space between cookies.

Bake for 10-12 minutes or until lightly golden around the edges. Allow to cool slightly before transferring to wire racks.