Preheat oven to 350 degrees. Line two baking sheets with parchment paper; set aside.

In the bowl of an electric stand mixer fitted with the paddle attachment, cream together butter, sugar, and salt until combined. Add in egg yolks and vanilla beat to combine.

Gradually add flour, beat until crumbly then add in 2 teaspoons milk, if needed add in another 1 to 2 teaspoons milk for a more pipe-able consistency (add as little as possible for less spreading during baking).

Pipe dough into rounds onto two ungreased baking sheets (if you have issues with cookies spreading chill them for 30 minutes on the baking sheet before baking).

Bake one sheet at a time in a preheated oven until golden brown on the bottom, about 12-16 minutes.

Let cool on baking sheet 5 minutes then transfer to a wire rack to cool completely. Spoon a 1/4 teaspoon raspberry jam into the centers of the cooled cookies. Store in an airtight container. Yields 24 cookies