Drain chickpeas and place them in a food processor. Add scallions, garlic, parsley, cumin, coriander, salt, egg and hot sauce. Mix baking powder with water and add mixture to food processor. Process until smooth. Transfer mixture into a small bowl. Add bread-crumbs until mixture forms a small ball without sticking to your hands. Pour the oil to a depth of 2 inches in a heavy saucepan or wok. Heat to 375 degrees. Roll into 16 ping - pong - ball sized balls and flatten slightly. Slip a few at a time into the hot oil, making sure they don't stick to the bottom. Cook, turning, for about 6 minutes, or until the balls are a dark, even brown on all sides. Remove with slotted spoon and drain on paper towels. Serve with chopped tomato, cucumber, lettuce chiffonade, hot sauce and Yogurt Sauce.
Mix together the yogurt, tahini paste, garlic and lemon juice. Thin out with water to make a smooth medium thick sauce. Season to taste with salt and pepper.