01 - Combine chicken thighs and buttermilk in a large bowl, ensuring all pieces are evenly coated. Cover and refrigerate for a minimum of 1 hour and up to overnight.
02 - In a separate bowl, whisk together flour, salt, black pepper, smoked paprika, and garlic powder until thoroughly blended.
03 - Remove chicken from buttermilk and allow excess liquid to drain. Dredge each piece in the seasoned flour mixture, pressing to ensure full coverage.
04 - Heat vegetable oil in a deep skillet or Dutch oven to 350°F. Fry chicken thighs in batches for 7–9 minutes per side, until golden brown and internal temperature reaches 165°F. Drain on wire rack set over paper towels.
05 - Preheat oven to 425°F. Combine flour, baking powder, salt, and pepper in a large mixing bowl. Toss in cold butter cubes and rub in by hand or use a pastry blender until mixture resembles coarse crumbs. Fold in cheddar cheese.
06 - Stir in milk and buttermilk just until dough comes together. Turn out onto a lightly floured surface and gently pat to 1-inch thickness. Cut into rounds with a 2.5-inch biscuit cutter.
07 - Arrange biscuits on a parchment-lined baking sheet. Bake for 13–15 minutes until tops are golden and centers are cooked through. Transfer to wire rack to cool slightly before serving.