If you would like to combine agar jelly and longan but you don’t have fresh longan fruits, then the dried version of longan is your choice. Often, longan fruits get slightly roasted, then peeled, dried and then get preserved in sugary solution. There are also simple dried longan in plastic bags.
Mix agar powder with sugar. Pour 700ml of water into the pot, bring it to a boil. Then add the agar mixture, stir well. Bring to a boil again until the jelly is evenly dissolved. Add 2 tablespoons of cocoa powder, stir well to dissolve the powder. Add the dried longan and cook for about 3 minutes, then turn off the heat. Do not cook the longan for too long, or they won't be crispy.