Preheat the oven to 375°F and line a baking sheet with parchment paper.
In a large bowl, combine the ground chicken, egg, ¼ cup buffalo sauce, diced celery, blue cheese, almond flour, salt, and pepper.
Mix until the ingredients are evenly distributed, then shape the mixture into a loaf on the prepared baking sheet.
Bake for 35 minutes, then brush the top with the remaining ¼ cup buffalo sauce and return to the oven for 10 more minutes.
While the meatloaf bakes, stir together the mayonnaise, sour cream, dried dill, and garlic powder in a medium bowl.
Add the sliced celery to the dressing and toss until evenly coated.
Let the meatloaf rest for 5 minutes before slicing and serving with the celery ranch slaw on the side.