In a large bowl, whisk together the flour and salt. Set it aside.

Using either a hand mixer or a stand mixer with a paddle attachment, beat the butter and brown sugars together on medium-high speed until combined and creamy. Beat in the vanilla.

On low speed, add in the flour mixture. Once it's all added in, switch to high speed until the dough comes together.

Turn the dough out into a lightly floured surface. Divide the dough equally in half. Roll each half into a long, roughly 8"in length and 2.5" in diameter. Tightly wrap each log with saran wrap and place it in the fridge to chill for at least 4 hours (and up to 5 days). Chilling this dough is necessary.

Once it's chilled for the mandatory amount of time, preheat the oven to 350°F. Line some baking trays either with parchment paper or a silicone baking may and set them aside.

Remove the logs from the fridge. Roll them in the coarse sugar if using, then slice into equal sized cookies. Place them spaced about 2" apart on the prepared baking trays.

Bake for 10-12 minutes, or until lightly browned around the edges. Allow them to cool on the baking trays, then transfer them to a wire rack to cool completely.

Store in an airtight container for up to 5 days.