If you want it even darker, add an extra teaspoon of cocoa rather than more chocolate, chocolate adds sweetness as well as richness. | A tiny pinch of espresso powder boosts chocolate flavour without tasting like coffee. | If it ever looks slightly split, blitz briefly with a stick blender and it will turn glossy again. | No blow torch? Put marshmallows under a hot grill for 30–60 seconds, do not walk away. | Adult version: Add a splash of dark rum, Baileys, or orange liqueur at the end. | Extra thick: Swap another 50 ml milk for cream. Think drinking chocolate rather than cocoa. | Spiced: A pinch of cinnamon or chilli works beautifully with dark chocolate. | Cool and store in the fridge for up to 2 days. Reheat gently on the hob, whisking well. | Freeze leftover hot chocolate in ice cube trays, drop a couple of cubes into hot milk for instant luxury hot chocolate later.