Brownies

Doneness

Top has a thin, papery, shiny crust; edges have pulled away from the pan walls by 1/8 inch; a toothpick in the centre comes out with a few moist crumbs (not wet batter). Sides feel firm when the pan is jiggled.

Oil & seasoning

Grease the pan with butter or pan-release spray and line the base with a parchment sling for easy lift-out. The batter itself contains the fat (butter or oil).

Season with: unsweetened cocoa powder, sugar, butter, eggs, vanilla, all-purpose flour, salt, chocolate chunks (optional).

Watch out for

• !Pan size matters more than recipe. A 9 × 9 inch pan will not fit a typical 5-quart basket — measure your basket before scaling a recipe. Use a 6 or 7 inch round / square pan for compact baskets, or step up to oven-style air fryers for larger pans.
• !Reduce the temperature by 25 °F vs the recipe's oven instructions and start checking at 18 minutes. Air-fryer convection is more aggressive than a conventional oven, so straight-from-the-box brownie box-mix instructions will overbake by 4–5 minutes.
• !Cool completely in the pan (at least 30 minutes) before lifting out and cutting. Hot brownies tear when cut and the centres look underbaked even when properly done — they set as they cool.
• !Skip the dark non-stick pans intended for ovens — their black surfaces over-brown the crust in air fryers. Light-coloured ceramic or anodized aluminium pans give a more even bake.