In a large bowl or the bowl of a stand mixer combine the granulated sugar and vanilla bean paste or vanilla beans and rub them together with your fingers until they are well combined and fragrant.

Add the butter (it should be at room temperature, but not oily), powdered sugar, and salt. Mix them together on low speed with a paddle attachment or on medium-low if using a hand mixer. Stir just until combined and creamy-don’t allow the mixture to become light and fluffy.

Add the egg yolk and beat it in for 1 minute. Dump in all of the flour at once and stir it on low until the flour has just been mixed in. You may want to stir in the last bit of flour by hand to avoid over-mixing.

Divide the dough into two equal portions (you can use a scale to make them exact), then place each of them on a sheet of plastic wrap.

Shape each half of the dough into a log about 9 inches long and 3-4″ across. Wrap it well with the plastic wrap.

Chill the dough for at least 3 hours, or up to 2 days.