Wash and trim any fat or unwanted pieces off of each chicken breast. One chicken breast should be big enough for two sandwiches.
Add chili powder, garlic powder, salt, white pepper, paprika and cumin to a medium bowl. Give it a quick whisk.
Dip each chicken piece into the rub. Move it around so that the chicken is evenly covered.
In a large bowl, pour buttermilk and add chicken to marinate.
Cover the bowl with plastic and transfer to the refrigerator for about 2 hours or even overnight. This step will ensure that the chicken is super moist!
For the Batter:
In a large bowl, combine flour, paprika, salt, garlic, ground pepper and cayenne pepper. Give it a whisk.
Heat a pot of vegetable oil to 350F over medium high heat. Roll out a paper towel station.
Coat each piece of chicken in the flour batter mixture.
Add up to 4 pieces to the pot to fry.
Cook for about 6 minutes.
Transfer to the paper towels to cool.
For the Coleslaw:
Chop up about ⅓ of the purple cabbage and ⅓ of the regular cabbage.
In a medium large bowl, add sour cream, ranch, caraway seeds, salt, sugar, lemon zest from ½ a lemon, green onions and chives. Add lemon juice and a splash of white wine vinegar. Give it a whisk.
Add in the cabbage slaw. Toss with tongs.
For the Assembly:
In a small bowl, add honey mustard, honey and hot sauce. Whisk until combined.
Chop the peppers into thin slices. Slice the avocados.
Add coleslaw, chicken, spicy sauce, pepper and avocados to each brioche bun.