Preheat a stove-top grill pan to medium-high and coat with cooking spray.
Place pineapple rings on hot grill and drizzle with maple syrup. Cook 2 to 3 minutes per side, until golden brown. Transfer grilled pineapple to individual dessert bowls (2 rings per bowl) and top each serving with 1/2 cup frozen yogurt and 2 tablespoons granola.