For the syrup, bring sugar, water and pandan leaf to a boil to dissolve the sugar. Allow to cool completely.
Combine (B) together to form a dough. Remove a piece of dough the size of a fist from the main dough. Put it in a saucepan and add about 125ml water. Cook over low flame until it turns gluey and starchy; keep stirring as it is being cooked. Leave aside to cool completely, then mix well with the main dough to form a flour paste.
Put lukewarm water in a bowl; add sugar and sprinkle with instant yeast. Leave aside for it to froth, then add this to the flour paste. Blend well and set aside for one to one and a half hours.
Combine sugar syrup with the flour paste and mix well. Leave aside to rest for 10 to 15 minutes.
Pour mixture into a well-greased 22cm square cake pan.
Steam cake over rapid boiling water over a moderate heat for 15 to 20 minutes.