Many of us will be wondering why do devotees offer jhangiri malai (in north india) and vadai malai (in south india) to the lord Aanjaneya.
This doubt was raised before Sri Kanchi Maha Periyava Sri Chandrasekara saraswathi swamigal. This was the explanation given by him.
When aanjaneya was a small kid, he saw the sun in the evening time before sun-set. For him it appeared like a fruit. So Aanjaneya being pavana kumaran (son of pavan or vayu), went so fast near sun and was about to swallow it. Then Lord Surya appeared before him and told that he should not do that and its against nature. Agreeing to that, hanuman came back.
This act of shadowing the sun, was appreciated by Lord Rahu (one of the nava grahas) who use to cause solar eclipse. He granted a boon to aanjaneya that people will worship him with substances made out of urid dal (ulundhu in tamil). So we are worshipping him with vadai and jhangiri made out of urid.
Why do people in north india worship with sweet jhangiri and people in south india worship with salt vadai?
It is because of the availability of sugar and salt. If you see in north India, sugar cane is in abundance. So sweet jhangiri. And in south india, salt is in abundance because of the sea shores. So the salted vada with pepper (found in abundance in kerala) is offered.