In a large pan, add water and turmeric powder and keep aside.
Peel the bananas and put them in the turmeric water for 20 minutes.
Remove the bananas from the turmeric water, slit the bananas vertically into two half`s and cut it into 1/2 inch slices and dry.
Heat the oil in a deep frying pan on medium heat.
When the oil is really hot, add the sliced banana and stir occasionally.
When it is half done, sprinkle the saline solution.
When the chips are golden and is crisp, take it out from oil and let them cool.
In a thick bottomed pan heat jaggery and water till jaggery melts. Strain this to removes any impurities.
Now reheat the strained syrup on a low to medium heat, stirring frequently till it reaches a thick consistency(nool paruvam).
Reduce the heat to low, add the fried banana pieces and mix well and stir continuously.
Now add the ginger powder, cardamom powder and cumin powder to this and stir constantly, so that all the slices are coated well with the jaggery.
Remove from fire and then add powdered sugar and mix well.
Wait for the pieces to be crisp.
Use only unripe plantains. Enjoy.