Brown butter chocolate chip cookies

Brown the butter over moderate, lowish heat, stirring constantly so the milk solids do not stick and burn; the butter cannot exceed 212F until all its water has boiled off, and the big bubbles give way to a fine foam just before it browns.

Take it a shade or two past golden brown for a really dark but not burned butter, then turn off the heat. Burned butter smells acrid and looks black.

Whisk in the two tablespoons of cold heavy cream.

Cool the mixture, stirring so it stays homogenous rather than setting solid against the bowl; an ice bath speeds this up.

Whisk in the brown and granulated sugars until very smooth and homogenous; no need to cream until light and fluffy, since air is not wanted.

Whisk in the eggs one at a time until well incorporated and the mixture turns silkier as the sugar dissolves.

Whisk in the vanilla.

Whisk the flour, baking soda and kosher salt together separately.

Chop half of each chocolate, keeping the dust, which blends into the dough and flavours it.

Whisk the dry ingredients into the wet, switching to a spatula if the dough is stiff, then fold in the chocolate.

Portion into level two-ounce scoops on a baking sheet, close together since they are only chilling; a one and a half ounce portion also works.

Cover and chill at least 12 hours and up to 48; even a couple of hours helps, and four is fine. The butter solidifies, some sugar recrystallises and the dough cures, giving a chewier cookie with more developed flavour and a wrinklier edge.

Press a disc of chocolate onto the top of every couple of cookies for a photogenic look.

After two days in the fridge the portions can be moved to the freezer.

Preheat to 350F and space six portions per baking sheet, as they spread a lot.

Bake 18 to 20 minutes, rotating halfway, to a golden brown edge and a pale, slightly shiny interior.

Cool on the baking sheets about five minutes while they set, then transfer to a wire rack.