In a large bowl or dish, combine yogurt, mustard and garlic. Add chicken and turn to coat. Cover and refrigerate 8 hours or overnight.
Preheat oven to 425°. In another bowl, mix flour, paprika, baking powder, salt and pepper. Remove chicken from marinade and add, 1 piece at a time, to flour mixture; toss to coat. Place on a wire rack over a baking sheet; spritz with cooking spray. Bake 40-45 minutes or until a thermometer inserted into chicken reads 170°-175°.