Slice-and-bake shortbread cookies

In a stand mixer bowl, combine room-temperature unsalted butter (soft enough to press, not melting) and vanilla extract.

Beat with the paddle until creamed and soft, without running it on high to pump in air.

Add the powdered sugar and salt and mix just until combined; scrape down the bowl.

Weigh the flour; too much makes dry, crumbly cookies that will not hold together. Variations: brown the butter, or add toasted pecans or walnuts, chocolate chunks, dried cranberries or sprinkles.

Mix on low, adding the flour slowly; scrape down and keep mixing until the dry, crumbly mixture comes together into a dough. Do not overmix.

On a lightly floured counter, shape the dough into a rectangular block (or a log for slice and bake).

Wrap in plastic wrap or waxed cloth and chill at least an hour, until firm.

Toward the end of chilling, preheat the oven to 350.

Cut into half-inch slices with a sharp knife; place on a rimmed baking sheet an inch apart and prick a pattern with a fork or skewer; trim edges with a knife if wanted.

Bake at 350 for about 10 minutes, rotating halfway, until the bottoms just take on colour.