Preheat your oven to 350°F (175°C) and line your cookie trays with parchment paper. If the air is warm, chill the cookie dough in the fridge for 30 minutes to prevent spreading.

In a large bowl, use a hand mixer to cream together the softened butter and granulated sugar until the mixture is light and fluffy.

Add the egg yolks and vanilla extract, mixing until well combined and smooth.

Gradually mix in the all-purpose flour and salt on low speed until large crumbles form in the dough.

Pour in the milk and mix until the dough absorbs the liquid. If the dough seems too dry, you can adjust with a little more milk.

Transfer the dough to a piping bag fitted with a large open star tip and pipe rosettes onto the lined cookie trays.

Bake for about 13 to 15 minutes, or until the edges are lightly golden brown.

Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.