Combine yogurt, mustard, garlic, pepper in a bowl, add mixture to a Ziploc bag. Add chicken pieces and turn to coat.
Zip the bag closed, and refrigerate for at least 30 minutes, up to 12 hours.
Preheat oven to 425°F
Line a rimmed baking/cookie sheet with foil, add a wire rack and spray with olive oil (lightly)
Blend together the flour, paprika, thyme, baking powder salt and pepper in a large Ziploc bag.
Take the chicken out of the marinade bag, shake off excess marinade, and add a piece to the flour bag.
Shake each piece until fully coated, then remove and shake off excess coating and place on an oiled rack set over a baking sheet.
Repeat with remaining chicken. Throw out the remaining marinade and flour mixture.
Lightly spray chicken with olive oil (using a mister) and bake until golden brown and when you get a reading of 160°F on a digital thermometer (test the thickest part of the meat). It will take around 45-60 minute for thighs, around 30-35 for drumsticks