First, combine all the brine ingredients in a large bowl and whisk them together. Add the chicken thighs, making sure they are fully submerged, and let them marinate for at least one hour or even overnight in the fridge for maximum flavor. While the chicken brines, mix all the dredge ingredients in a separate bowl.
Preheat your oven to 425°F (220°C). In a large bowl, whisk together the flour, baking powder, baking soda, and salt. Use a box grater to grate the frozen butter directly into the flour mixture and toss to combine.
Next, pour in the cold buttermilk and honey, stirring with a spatula until a shaggy dough forms. Turn the dough onto a floured surface, pat it into a rectangle, and fold it like a letter. Repeat this folding process at least three times to create those delicious, flaky layers.
Roll the dough to a 1-inch thickness and use a biscuit cutter to cut out your biscuits. Place them in a cast iron skillet, brush the tops with the melted honey butter mixture, and bake for 13-15 minutes until tall and golden brown.
Heat your frying oil in a Dutch oven to 350°F (175°C). Take the chicken from the brine and coat it thoroughly in the dredge mixture, pressing firmly to adhere. Fry the chicken in batches for 7-8 minutes, until golden, crispy, and cooked through.
Let the fried chicken rest on a wire rack. To assemble, slice a warm biscuit in half, place a piece of crispy chicken inside, and brush everything generously with more of the honey butter. Serve immediately and enjoy the deliciousness.