Preheat the oven to 200°C. Grease a 23cm tin thoroughly with 25g of the butter, then dust the inside of the tin with flour.
Using a food mixer, blend the remaining butter and sugar together. Slowly add the golden syrup, treacle, eggs and vanilla extract to the butter mixture and continue mixing. Turn the mixer down to a slow speed and then add the flour. Once all the ingredients are combined, turn off the mixer.
Place the dates in a saucepan with 300ml water and bring to the boil. Puree the water and date mixture and add the bicarbonate of soda. While it is still hot, quickly add this mixture to the egg mix. Once the mix is combined, pour into the prepared tin and bake for 40 to 45 minutes until the top is just firm to the touch.
Remove the pudding from the oven and allow it to cool. Turn out of the tin and cut into squares.
To make the sauce, melt the butter and sugar together in a small pan, add the cream and bring to the boil. Simmer for a few minutes until the sauce reaches the desired consistency. To serve, reheat the sponge in a microwave, or for five minutes in a 180°C oven. Place onto a plate with lots of the sauce on top and a scoop of vanilla ice-cream if you wish.
Recipe from Desserts by James Martin (Quadrille Publishing Limited).