Sauce: melt butter, muscovado, and cream; boil 3 minutes to glossy toffee. Stab the warm sponge all over and pour half through; broil 1 minute; serve with the rest and cold cream.
5 min — timer available in cooking mode
Why this works
Muscovado's molasses depth is the recipe. Light brown sugar makes a nice cake; muscovado makes THE pudding.