Self-Saucing Pudding—Storing?
Here's your answer, directly from the creator of the recipe:


  This dish is terrific if left for an hour or so after cooking as it
  gives the saucy bit and the cakey bit some time to separate a little.
  I have devoured leftovers of this 24 hours later, after i left them in
  the fridge. In all honesty after being left for this time it's very
  different to what it's like warm - more like a gooey pudding than cake
  and a sauce, but absolutely delicious. I doubt very much that it would
  reheat as it would dry out (although you could try it briefly in the
  microwave if you have one).
  
  I hope that helps.
  
  By the way, the Guardian printed a version of this recipe which had
  one of the ingredients (milk) missing from the method. Hopefully the
  one you're using is the correct one, but if you do find the milk is
  missing, the correct version is on my website
  
  Best wishes
  
  Sue


(just to make sure: I'm not Sue, this a copy of the email she sent me in response to the forwarding of your original question)