Make sure all your ingredients are measured, unwrapped, and within reach. Once the syrup is ready, things move quickly, and there’s no time to pause.

Add the sugar, glucose (or corn syrup), and water to a heavy-based saucepan. Place over medium heat and stir gently until the sugar has completely dissolved, and the mixture looks clear.

Once dissolved, stop stirring. Continue cooking, allowing the syrup to bubble steadily, until it reaches soft crack stage (around 280°F) on a candy thermometer.

Carefully stir in the peanuts. Continue cooking, stirring occasionally, until the mixture deepens to a rich golden amber colour and reaches hard crack stage (around 300°F).

Watch closely at this point — the temperature rises quickly, and the sugar can burn if left unattended.

Remove the pan from the heat. Immediately add the butter, vanilla, baking soda, and salt.

Stir quickly and confidently. The mixture will foam up and lighten in colour. This is exactly what you want and is what gives the brittle its crisp, airy structure.

Pour the hot mixture straight onto the prepared baking sheet. Tilt the tray or use a buttered spatula to spread it into a thin, even layer. Don’t overwork it — the less handling, the better the texture.

Leave to cool completely, then break into pieces by hand.