Using an electric hand mixer, beat the butter in a large mixing bowl until smooth.
Add the powdered sugar and vanilla extract and mix until fully combined, scraping the sides of the bowl as needed.
On low speed, slowly begin to mix in the flour (and salt if your using unsalted butter). Slowly increase the speed of the mixer until all the flour is added. The dough may seem dry during this process but it will come together into a thick, sandy texture.
Press the dough into a ball, and cover it with plastic wrap. Let it cool in the fridge for about 30 minutes.
While the dough is cooling, preheat your oven to 350℉, line your cookie sheets with parchment paper, and get the remaining powdered sugar ready for rolling.
Scoop about 1 tablespoon of dough and roll it into balls, placing them on the parchment lined cookie sheets about 2 inches apart. Bake in the oven for 12-15 minutes until the bottoms are just browned.
Let the balls cool for 5-10 until cool enough to handle, and roll them in the powdered sugar. Return them to the cookie sheet and allow them to cool completely before rolling them a final time in the powdered sugar so you get the perfect coating.