Combine yogurt, mustard and garlic in a large bowl. Put chicken into bowl and toss until evenly coated. Cover and place in refrigerator for at least 6 hours (up to overnight)
Preheat oven to 425deg.
In a bowl combine flour, salt, pepper, paprika, and baking powder. Dunk each of piece of chicken into the flour mixture and thoroughly coat all sides. Line out (alternating direction, so you can fit them all in) on a baking sheet with a cooking rack. Once done with all pieces, spray with cooking spray and then put into oven for 45 minutes.