To make the brine, mix the buttermilk with all of the spices in a large bowl. Transfer to a gallon-sized resealable plastic bag. Add the chicken, turn to coat, and refrigerate overnight.
Heat 1 inch of canola oil in a large heavy-bottomed high-sided skillet over medium-high heat until it reaches 375°F. In a shallow bowl, whisk the flour with the spices and add the chicken pieces. Turn to coat in the flour and let the chicken rest in the flour until the oil gets hot. Tap off the excess flour and add as many pieces of chicken to the skillet as you can. Fry until browned, 6 to 8 minutes. Turn the chicken over and fry until the chicken is deeply browned on the other side, about another 6 to 8 minutes. Using tongs, transfer the chicken pieces to a paper towel–lined plate to drain. Serve while warm or at room temperature.