In a medium bowl, combine the cumin, paprika, cayenne, turmeric, sugar, black pepper, salt, garlic, and lemon juice.
Using a sharp knife, slash the chicken in a couple of places. Rub the spice paste all over the chicken, place it in the bowl, and cover with plastic wrap. Let marinate in the refrigerator for at least 3 hours.
Preheat the oven to 350°F (177°C).
In a small roasting pan, place the chicken and all of the paste. Brush or drizzle with sunflower oil.
Bake for 20 minutes, then turn over and bake until cooked through, about 20 minutes more, depending on the size of the chicken pieces. Baste 2 or 3 times during cooking.
Move to a plate, spoon the degreased drippings over the chicken, and let cool.