Begin by marinating the cut-up fryer chickens in 1 quart of buttermilk. Allow them to soak for at least 30 minutes to tenderize and flavor the meat.
In a large mixing bowl, whisk together the flour, seasoned salt, black pepper, dried thyme, paprika, and cayenne pepper.
In a separate bowl, mix the remaining 1/4 cup of buttermilk with the 1/4 cup of milk.
Create a well in the center of the dry ingredients and pour in the buttermilk mixture. Gently stir until just combined; avoid overmixing.
Turn the dough out onto a floured surface and knead gently about 5-6 times, just until it comes together. Pat it into a rectangle about 1-inch thick.
Using a floured biscuit cutter, cut out your biscuits and place them on a greased baking sheet. Gather and re-pat the scraps to cut out additional biscuits.
Preheat your oven to 450°F (232°C). Bake the biscuits for 12-15 minutes or until golden brown on top.
While the biscuits are baking, heat oil in a cast iron skillet over medium-high heat. Remove the chicken from the buttermilk and dredge it in the flour mixture. Fry until golden brown and cooked through, about 15-20 minutes.
