Butter the malt loaf slices, spread with marmalade, and cut into triangles.
Grease a 1.2 litre oven-proof dish and arrange a layer of malt loaf at the bottom.
Repeat layers of malt loaf and sultanas until all ingredients are used.
Gently heat milk and cream in a pan until just before boiling.
Whisk eggs, caster sugar, and cinnamon in a bowl.
Gradually whisk the warm liquid into the egg mixture until fully incorporated.
Pour custard over the loaf, sprinkle with demerara sugar, and stand for 30 minutes.
Preheat the oven to 180°C.
Bake for 30 to 40 minutes until the custard is set and the top is golden-brown.
Mix crème fraîche with orange zest and serve with the slightly cooled pudding.