01 - Preheat oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease thoroughly.
02 - Combine all-purpose flour, baking powder, baking soda, salt, and black pepper in a large bowl. Whisk until evenly blended.
03 - In a separate bowl, whisk together buttermilk, eggs, melted butter, and Buffalo sauce until fully incorporated.
04 - Add the wet mixture to the dry ingredients and stir gently with a spatula until just combined. Avoid overmixing.
05 - Carefully fold in shredded chicken, crumbled blue cheese, shredded cheddar cheese, and chives if using.
06 - Evenly distribute the batter among the muffin cups, filling each approximately three-quarters full.
07 - Bake for 22 to 25 minutes until the tops are golden and a toothpick inserted into the center of a muffin emerges clean.
08 - Let muffins cool in the pan for 5 minutes, then transfer to a wire rack. Serve warm or at room temperature.