Add the butter, sugar, egg yolk, flour and salt to a food processor. Pulse together. Add the water and pulse until the dough comes together into a ball.

Remove to a floured surface and press together until only lightly tacky, not sticky. Cut into two and wrap both halves in plastic wrap.

Chill in the fridge for 1-2 hours.

Once the dough is nearly done chilling, preheat the oven to 375 degrees Fahrenheit. Wrap the clothespins in small sheets of foil.

Wrap each strip of dough around a prepared clothespin, ensuring the dough overlaps about ¼ inch. Place on a parchment lined baking sheet with the ends of the strip of dough facing down. Repeat with the second half of the dough.

Let the cookies cool for 2-3 minutes before gently removing the clothespins. Let them cool the rest of the way on a cooling rack.

Remove from the heat and add to a heat-proof bowl or quarter sheet pan. Cover with plastic wrap so the plastic touches the top of the mixture and prevents a film from forming. Chill in the fridge for 40 minutes

Add the room temperature butter to a stand mixer and whip with the whisk attachment for about 8 minutes, until the butter is light and fluffy.

Add the flour mixture to the butter one scoop at a time until it is all incorporated

Scrape down the sides and bottom of the bowl and switch to the paddle attachment. Add the vanilla and salt and beat on medium-high for 10-13 minutes, until smooth and fluffy.