Combine whole milk (or water), 1/4 cup kosher salt, smashed garlic cloves, black peppercorns, and bay leaves in a large bowl. Pierce the chicken pieces a few times with a knife, submerge them in the liquid, cover, and refrigerate for at least 3 hours.
In a large bowl, whisk together the flour, cornstarch, 1 tbsp kosher salt, white pepper, black pepper, garlic powder, onion powder, cayenne pepper, smoked paprika, and baking powder until perfectly even.
Transfer exactly 1 cup of the dry seasoning mix into a smaller bowl. Add 1 cup of cold water and whisk vigorously to create a smooth wet batter.
Remove the chicken from the fridge. Take 2 tablespoons of the leftover soaking liquid and drizzle it over the remaining dry flour mix. Gently rub it in with your fingers to create small dough clumps (craggy bits).
Dip a piece of chicken into the wet batter, letting excess drip off. Drop it into the clumpy dry mix and press the seasoned flour firmly onto the meat until fully coated. Let the coated chicken rest on a clean wire rack for 10 minutes.
Heat neutral cooking oil in a heavy Dutch oven to 350°F. Carefully fry the chicken in small batches for 8-12 minutes until deep golden-brown and the internal temperature reaches 165°F. Drain on a clean wire rack.