Preheat a grill to medium, and preheat the oven to 350 degrees F.
To make the spice rub, combine the peanuts, brown sugar, salt, cayenne, ground bay leaf, cloves, nutmeg, and cinnamon in a bowl. With a small, sharp knife, score each thigh and drumstick twice on each side, 1/2-inch deep. Place the chicken in a large bowl. Add the spice rub and toss to coat evenly.
Grill until marked, about 3 minutes per side. Transfer to a roasting pan or baking sheet lined with aluminum foil. Roast in the oven until browned and cooked through, and the juices run clear when pierced with a fork, about 35 minutes. Remove from the oven and transfer to a plate. Cover to keep warm.
Place the tortilla on the hot grill and cook for 10 seconds on each side to mark. Remove and tear or cut into small pieces. (Alternately, fry the tortilla until crisp in 360 degree F. oil.)
Drain 1/4 cup of the pan juices into a small saucepan. Add the chicken stock, lime juice, chili powder, salt, and tortilla pieces. Bring to a boil. Reduce the heat and simmer for 5 minutes. Transfer to a blender, add the peanut butter, and process on high speed until smooth.
Divide the chicken and sauce among 4 plates and serve immediately.