Preheat your oven to 350 °F (175 °C).

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

Add the vanilla, flour, and kosher salt. The mixture will become crumbly—use your hands to gently knead it into a cohesive dough ball.

Wrap the dough in plastic wrap and form it into a log approximately 12 inches long and 1½ inches in diameter. Chill in the refrigerator for at least 30 minutes (or longer for easier slicing and better texture).

Once chilled, slice the log into rounds about ¼‑inch thick.

Arrange the cookie slices on a baking sheet and bake for 10–13 minutes, or until the edges are just starting to turn golden.

Remove from the oven and let the cookies cool completely—they’ll firm up with that signature delicate, crumbly texture.