In medium bowl, cover chickpeas with at least 2 inches cold water. Let soak at least 12 hours, or overnight, at room temperature.

To make falafel bites: Drain soaked chickpeas, rinse well in colander and let stand.

In bowl of food processor, process parsley and cilantro until chopped herbs stick to sides of bowl. Do not scrape down. With motor still running, drop garlic through feed tube; it will also stick to sides of bowl. Remove lid, add onion and pulse to chop well. Add chickpeas, cumin, salt and baking powder. Scrape everything off sides of bowl and process until mixture is well chopped and looks mealy. Add flour and pulse to blend. Cover mixture and chill at least 1 hour.

Using 1-ounce scoop or tablespoon, drop 2-tablespoon mounds of chickpea mixture onto plate. Shape into balls, stuffing one grape inside each.

Heat oven to 350 F. Line baking sheet with foil then parchment paper.

Place falafel balls on sheet and spray with vegetable oil cooking spray. Bake 20 minutes, turning 1-2 times with tongs, until golden brown.