1.Preheat oven to 180°C (160°C fan forced). Grease eight ¾ cup (180ml) metal dariole moulds.
2.Place chocolate and butter in a medium heatproof bowl over a medium saucepan of gently simmering water (don’t let water touch base of bowl). Stir, occasionally, until melted and smooth. Remove from heat.
3.Beat eggs, egg yolks and sugar in a medium bowl with an electric mixer until thick and pale. Fold in sifted flour and ground hazelnuts, gently stir in chocolate mixture until just combined. Pour mixture into moulds, place on an oven tray.
4.Bake puddings 25 minutes or until a skewer inserted into the centre comes out with moist crumbs attached.
5.Meanwhile, make crème anglaise. Bring milk and cream almost to the boil in a small saucepan. Whisk egg yolks, sugar and vanilla in a medium bowl until smooth, gradually whisk hot milk into egg yolk mixture. Return mixture to pan, stir with a wooden spoon over medium-low heat until custard thickens and coats the back of the spoon. Do not boil.
6.Carefully run a knife around edge of moulds, turn warm puddings onto plates. Dust with cocoa, drizzle with warm crème anglaise.