Preheat oven to 170C/325F/Gas 3.

Combine dates and bicarbonate of soda in a pan.

Cover dates with water and simmer until it forms a thick mush.

Butter one side of each brioche slice or half of each brioche roll.

Layer brioche and date mixture in an oven-proof dish, starting and ending with a brioche slice.

In a bowl, beat egg yolks, vanilla, and caster sugar until combined.

Heat heavy cream until scalding.

Gradually mix the hot cream into the egg mixture.

Pour the custard mixture over the layered brioche.

Let it sit for 15-20 minutes to allow the brioche to soak up the custard.

Sprinkle the top with brown sugar.

Bake for 40 minutes, or until the custard has set and the top is golden brown.

While the pudding is baking, prepare the sauce.

Combine butter, golden syrup, and brown sugar in a saucepan.

Bring the mixture to a boil, stirring until smooth.

Remove the sauce from heat and stir in the heavy cream and brandy.

Return the sauce to low heat briefly to warm.

Serve the warm sauce with the pudding.