Caramelise the sugar in a small saucepan over medium heat.

Deglaze with the orange and lemon juices.

Add the pumpkin cubes and cook slowly until soft.

Purée finely, then allow to cool completely.

Pass the mixture through a fine sieve.

Combine the cream with the strained pumpkin mixture.

Pour into a whipping siphon, insert one charger, and shake well.

Chill in the refrigerator for at least 2 hours.

When ready to serve, pour hot chocolate into a cup.

Spray on the pumpkin foam and sprinkle with brownie bits.