1. Combine the flour and salt on a large square of waxed paper.

2. In the large bowl of a stand mixer on medium speed, beat the butter and brown sugar for 3 to 5 minutes, until light and fluffy. Scrape down the sides of the bowl. Reduce the speed to low and add the vanilla extract, mixing to combine. Add the dry ingredients in 2 increments, incorporating after each addition. Divide the dough in half and place each half on a large square of waxed paper. Form each half into a log, wrap loosely in the waxed paper and refrigerate for about 45 minutes or until firm enough to shape.

3. When the dough is firm, lightly dust your hands with flour. Roll each log of dough under the palms of your hands into an 8-inch-long cylinder (if the dough becomes sticky, refrigerate it briefly), then roll it up tightly in waxed paper or plastic wrap, using the paper or wrap to help make a smooth, compact log. Refrigerate for 1 1/2 to 2 hours, until quite firm.

4. When ready to bake, position the racks in the upper and lower thirds of the oven. Preheat the oven to 350F. Line several large baking sheets with parchment paper or silicone liners.

5. Work with 1 log of dough at a time, keeping the second one refrigerated. Using a sharp, heavy knife, cut the dough into 1/4-inch-thick slices and place them about 2 inches apart on ungreased heavy baking sheets (if you don't have heavy baking sheets, reduce the baking time by a minute or two). Bake for 10 to 12 minutes, rotating the sheets halfway through baking, until the cookies are golden brown around the edges. Let cool on the sheets for 3 minutes, then transfer the cookies to wire racks to cool completely.