Coat a waffle iron with cooking spray, and preheat.
Combine baking powder and potato pancake mix in a large bowl. Place milk, sour cream, and egg in a medium bowl; stir well with a whisk. Add milk mixture to potato pancake mixture, stirring until smooth. Fold in cheese and chives.
Spoon about 1/2 cup batter onto hot waffle iron, spreading batter to edges. Cook 3 to 5 minutes or until done; repeat procedure with remaining batter.