Tap this crispy, weightless meringue cookie and it sounds hollow. But take a bite and the outside shatters, melts, then gives way to the chew of chocolate chips and nutty bits. More a confection than cookie, it is sweet, crunchy air. These treats whip up easily and bake all by themselves. Put them into a hot oven, switch it off, and forget them. Do not disturb them for hours—preferably overnight. Slow drying crisps them up. My mom, Muriel, of Olympic Seoul Chicken fame, wouldn’t settle for plain-old boring meringues. So she folded in chocolate and nuts. My two older brothers named them Meringue-a-Tangs—as fun to say as to eat. We thank our family dog,…