Place mixed fruit, almonds and orange rind in a large bowl. Bring orange juice and liqueur to a simmer in a saucepan over low heat. Pour over mixture. Cover and place in the fridge overnight to soak.
Use an electric mixer to beat the butter, sugar and mixed spice in a bowl until pale and creamy. Add the eggs, 1 at a time, beating after each addition. Add to the fruit mixture and combine. Stir in the breadcrumbs and flour.
Grease a 2L (8 cup) pudding basin. Line base with a disc of baking paper. Dust sides with flour. Spoon in mixture. Smooth the surface. Cut a 30cm square of baking paper and foil. Place paper on top of foil. Fold the centre to pleat. Place over basin, foil-side up. Use a lid or tie string twice around the top to secure. Scrunch paper and foil tightly around the rim of the basin.
Place an upturned heatproof saucer in the base of a large saucepan. Place the pudding basin on saucer in the pan. Add enough boiling water to the pan to come halfway up side of the basin. Bring to a simmer over medium heat. Cook, covered, adding more boiling water as necessary, for 6 hours or until a skewer inserted into centre comes out clean. Set aside for 10 mins before turning on a serving plate.
To make orange butter, use an electric mixer to beat the butter and sugar in a bowl until pale and creamy. Add liqueur or orange juice, orange rind and mixed spice and beat until well combined.
Serve pudding with ice-cream, orange butter and candied orange, if desired.
