Slice-and-bake butter cookies by the creaming method

Bring the ingredients to room temperature; the butter should be really soft. Cut colder butter into smaller pieces with a bench scraper.

Put the butter and sugar in the mixer bowl and cream with the paddle on low speed until fluffy.

Crack the room-temperature egg on a flat surface and beat it with a fork; trickle it slowly into the butter and sugar so the mixture stays fluffy, not wet and glistening.

Add the dry ingredients all at once and mix on low speed until just combined, when the flour disappears.

Chill the dough about 10 minutes if needed, then roll it into a log by hand or with parchment; if the kitchen is warm, freeze 10 minutes and roll again.

Firm the log in the freezer about 20 minutes or the fridge about half an hour; it keeps frozen about two months.

Trim the end and slice with a chef's knife, rotating the log 90 degrees each cut to keep it round; cut quickly while cold.

Bake on a silicone sheet (more spread), parchment (less spread) or in a ring (straight edge); sprinkle a little fleur de sel on top first.

Bake about eight minutes.