we use this one ALL the time, it's easy as it goes in the microwave!!

60g butter,
1 1/2 cups s/r flour
1/2 cup caster sugar
1/4 cup cocoa
3/4 cup milk
1 tsp vanilla
1 cup brown sugar
1/3 cup cocoa extra
2 cups boiling water

melt butter in microwave
stir in flour, caster sugar,cocoa milk and vanilla beat with wooden spoon til smooth
combine brown sugar and extra cocoa sift over mixture
pour boiling water over the mixture
cook for 12-13 minutes on MEDIUM allow to stand for 5 mintues before serving.

yummo.....