Sift flour, baking powder, salt and sugar together in a bowl.
Make a well at the center and add oil, egg yolks and mango jam in water, mix until smooth. Set aside.
Beat egg whites with cream of tartar until soft peaks form. Add sugar gradually and continue beating until stiff but not dry.
Fold in egg yolk mixture into the egg white mixture until thoroughly blended.
Divide batter equally between the prepared pans.
Bake for 15-20 minutes or until done. Invert on a wire rack to cool for 5 to 10 minutes.