Start by making the cinder toffee. Use a baking sheet with a silicone mat, or grease a
baking tray with oil if you don’t have one.
Place the sugar, golden syrup, salt and vinegar into a large, deep, heavy‑based saucepan
with one tablespoon of water. Heat gently to dissolve the sugar, then boil until the
liquid turns a golden caramel colour.
Remove from the heat, add the bicarbonate of soda and whisk rapidly — the mixture will
froth up! Tip onto the prepared tray and leave to cool. Break into nuggets once set.
Preheat the oven to 180°C or 160°C fan. Place 12 large muffin cases into a muffin tin.
Mix the cocoa and strong coffee into a smooth paste. Add all remaining cake ingredients
and beat for 2 minutes with an electric mixer (or 3 minutes by hand).
Divide the mixture between the cases and bake for 25 minutes or until well risen and
firm to the touch. Leave to cool in the tin to prevent the cases peeling away.
Make the frosting by beating the butter, icing sugar, chocolate hazelnut spread,
hazelnut essence and milk until smooth, soft and creamy. Place into a piping bag
fitted with a large star nozzle.
To caramelise the hazelnuts, place the caster sugar and water into a small heavy
saucepan. Heat gently to dissolve, then boil rapidly until golden. Dip the hazelnuts
into the caramel and place onto baking parchment to harden.
Rub the chocolate buttons with a little vegetable oil to give them a lovely shine.
To finish, pipe a swirl of frosting onto each cupcake, top with a shiny chocolate
button, three caramelised hazelnuts and a sprinkle of toasted chopped hazelnuts.