Mix all the dry ingredients in a bowl. Make a well and pour in the liquid ones.
Stir with fork or spatula to a homogeneous mixture.
Pour into oiled and sprinkled with cocoa tray (11 3/4″ (30 cm) x 8″ (20 cm)).
Cut the cooled cake into pieces.
Put all the ingredients for the topping on the stove to heat up, stir until the butter melts.
Using a spoon, pour the hot topping over the cake and leave to sit for a bit.