In a large mixing bowl, beat the softened butter and granulated sugar together on medium speed until very light and fluffy, about 3–4 minutes.
Mix in the egg, vanilla bean paste, orange juice, and milk until smooth and fully incorporated.
Add the flour and salt and mix on low speed just until a soft, pipeable dough forms.
If the dough feels too stiff to pipe, add 1/2 tbsp more milk.
Transfer the dough to a piping bag fitted with a large star tip (open star or French star works best).
Pipe swirls, rosettes, or S-shapes onto a parchment lined baking sheet, spacing them 1–2 inches apart. I make them small, around 1 ½ inch round cookies.
Bake at 350°F for 9-10 minutes, until the edges are just set and the tops look matte.
Do not brown the tops, these cookies stay pale.
Let cookies cool on the baking sheet for 5 minutes, then transfer to a wire rack to finish cooling.