Place half the sugar in a small saucepan over medium-high heat; cook about 3 minutes, swirling pan often, until sugar is deep golden. Remove from heat; carefully pour in the water all at once ­ mixture will boil. Return to heat; cook for further 3 minutes or until toffee has mostly dissolved. Stand 5 minutes.

Grease a 1.5-litre (6-cup) pudding steamer and lid; line base of steamer with baking paper.

Sprinkle two-thirds of the crystallised ginger onto the base of steamer; drizzle with honey.

Beat butter, remaining sugar and spices in a small bowl with an electric mixer until light and fluffy. Beat in eggs, one at a time. Stir in sifted flours and remaining crystallised ginger, then milk and cooled toffee, in 2 batches.

Pour pudding mixture into steamer. Cover steamer with the lid or pleated baking paper and foil secured with string. Place steamer in a large saucepan with enough boiling water to come halfway up the side of the steamer; cover pan with a tight-fitting lid. Boil pudding about 1½ hours, replenishing the water as necessary to maintain its level. Remove steamer from pan; stand 10 minutes before turning onto serving plate.

Meanwhile, make calvados custard. Split vanilla bean; scrape out seeds. Place milk, cream and vanilla seeds in a medium saucepan; cook, stirring, over medium heat until mixture comes to a gentle simmer. Remove from heat. Whisk egg yolks, sugar and cornflour in a medium heatproof bowl until combined. Strain hot milk mixture over egg yolk mixture, whisking constantly. Return mixture to cleaned pan; cook, stirring, over low heat about 2 minutes until custard thickens and coats the back of a wooden spoon. Stir in calvados.

Serve pudding with custard.