Pappulu, Putnala pappulu or Dalia are made from chickpeas. Not the regular white chickpeas but from black chickpeas, a special variety of chickpeas specific to India and commonly sold under the name “kala chana”. Preparing dalia and puffed rice are cottage industries in India. We call them “Bhattis” and almost every town has few bhattis, where they not only make but also sell both pappulu and puffed rice. There were couple of bhattis near our home in Nandyala and we were used to buy them fresh and hot from those places.
The process to prepare roasted chana dal (Dalia, pappulu) is - first whole chickpeas are soaked in water for several hours, and then after draining, chickpeas are roasted in big caldrons like oats under controlled fire for several hours continuously mixing. Until the chickepas turn to crisp, golden color. Once the roasting process is completed, the hulls of chickpeas will be removed and each chickpea will be split into two equal pieces. This whole soaking-roasting process intensifies the taste of chickpeas and turn them into light yellow, mildly sweet pappulu or dalia.
Among all the lentil types available in an Indian store, these are only one which you can just open the packet and pop them into mouth, because they taste great. As kids and even now, we love to eat them as they are or mixed with murmuras. They are a snack item for us like popcorn. If you are from South India, I assume you already know how the roasted split chickpeas (Pappulu, Putnala Pappu, Bhuna Chana, Dalia)) taste. For those of you who don’t, you must try them at least once. They are usually sold in Indian grocery shops under the label “Dalia” in lentil section. They are really great tasting, guilt free snack.
Instead of besan (gram flour), we use pappulu podi(dalia powder) for everything - to season the curries, to prepare chutneys etc, mainly because it is not only adds sweetness to the dish and also acts as a thickening agent. This following recipe is a dry powder recipe of my amma’s. Prepare and store in a jar and add it to the curries or in chutneys.
Recipe:
1 cup Pappulu 
6 to 8 dried red chillies
2 tablespoons of coconut powder or dried pieces of coconut
1 tablespoon of cumin
1/2 teaspoon of salt or to taste
4 garlic cloves (this is optional, even without garlic this powder tastes great)
Mix all off them together and take them in a clean, dry mixie jar. Without adding any water make fine powder of them. Store the powder in an airtight container. Will stay fresh as long as it remains dry.
What I do with this powder: 
Tastes great when mixed with plain rice and ghee.
Also great when mixed with rice, dal (tomato or spinach) and ghee.
To sprinkle on Masala Dosa
To dunk Idlis and also with Upmas particularly with my new favorite-oatmeal upma.
Good with vegetable curries - mainly cabbage, bell pepper, beans and Indian variety beans.
(I usually sprinkle one tablespoon of this powder before turning off the heat while making the curries).
To prepare chutneys, mainly for coconut chutney.