In shallow dish, whisk together flour, chili powder, cumin, salt and cayenne. Pour buttermilk into a medium-size bowl.
Dip each wing into the buttermilk, shaking off excess. Roll in the flour mixture and place on a baking sheet fitted with wire rack. Refrigerate while heating oil.
Place oil in large lidded heavy-bottom skillet. Heat oil to 365 degrees F over medium-high heat. Add chicken and fry, covered, for about 5 minutes, until browned and crispy. Turn and fry an additional 5 minutes. If chicken is browning unevenly, move around in skillet with tongs. Transfer chicken to paper towels.
In a small bowl, mix together the Ranch dressing, buttermilk and scallions. Serve with the wings.
