How to Make It
Preheat the oven to 375°. Spray a large non-stick baking sheet with oil. In a large bowl, whisk the mayonnaise and yogurt with 1 tablespoon of the salt and 1/2 teaspoon each of the cayenne and black pepper. In a large resealable plastic bag, mix the polenta with the flour, the remaining tablespoon salt and the remaining 1/2 teaspoon cayenne. Add the chicken to the yogurt mixture and turn to coat completely. Transfer the chicken to the plastic bag, a few pieces at a time; seal and shake to coat.
Arrange the chicken on the prepared baking sheet and spray lightly with vegetable oil. Bake on the lowest rack of the oven for 30 minutes or the chicken is cooked through and golden on the bottom.
Using tongs, carefully turn each piece of chicken and bake for 5 minutes longer, until the undersides are golden. Blot the chicken with paper towels, transfer to a platter and serve.