Boil the kettle. Tip the dates into a heatproof bowl with the bicarb and vanilla extract, then pour over 200ml boiling water and leave to soak for 30 mins. Meanwhile, butter a 20cm square baking tin.

Heat the oven to 190C/170C fan/ gas 5. When the dates have soaked and cooled, tip them along with their soaking liquid into a food processor and pulse to chop. Tip the rest of the sponge ingredients and a pinch of salt into the food processor and pulse to make a batter. Scrape the batter into the tin and bake for 40-45 mins, or until the pudding is firm to the touch and a skewer inserted into the centre comes out clean.

While the pudding is baking, make the sauce. Tip the butter and sugar into a saucepan and warm over a medium heat, stirring constantly until the sugar has dissolved and the butter has fully melted. Bubble for 3 mins until the mixture is thick, then stir in the cream and simmer, stirring, for 2 mins until you have a toffee sauce. Serve the pudding warm, cut into squares and drenched in the sauce with vanilla ice cream on the side, if you like.