Heat a clean, dry heavy-based saucepan over high heat for 1 minute or until hot, then add the caster sugar and cook without stirring for 8–10 minutes or until melted and a dry caramel forms. Stir in the almonds, tossing to coat them with the caramel. Stir in the butter and the salt and cook for 3 minutes or until the almonds are toasted; the butter will loosen the mixture.<