This gorgeous dessert is served with a homemade cinnamon hazelnut brittle.
Place the gelatine sheets in a small bowl of cold water and leave for 5–10 minutes, until softened. Set out 4 x 175ml dariole moulds or ramekins.
Put the cream, milk, sugar and coffee into a small heavy-based saucepan. Place over a medium-low heat and bring to a simmer. Immediately remove from the heat.
Squeeze out the soaked gelatine leaves and stir them into the hot cream, mixing well until completely dissolved. Set aside to cool slightly.
Meanwhile, rinse the moulds or ramekins in cold water, but don’t dry them. This will make the panna cottas easier to turn out once set. Pour the panna cotta mixture through a sieve into a jug, then pour into the waiting moulds. Place in the fridge and leave to set overnight.
Preheat the oven to 180ºC/Gas 4.
Meanwhile, make the brittle. Put the hazelnuts on a baking tray and place in the oven for 10 minutes, or until golden.
Line another baking tray with greaseproof paper or a silicon mat. Sprinkle the sugar into a heavy-based frying pan and place over a medium heat until the sugar dissolves and begins to turn golden. Swirl the pan to ensure it caramelises evenly. Once it is dark golden, add the toasted hazelnuts and ground cinnamon, swirl to combine, then tip into the prepared baking tray. Set aside until completely hard.
To serve, dip the moulds in boiling water for 5 seconds. Place a plate over each one and, holding tightly, invert both, giving the mould a little shake if necessary. Break the brittle into shards and serve alongside the panna cottas.