Remove any giblets from inside the chicken then place the chicken breast-side down on a flat surface.
Find the backbone running down the center of the chicken then use a pair of sharp shears to cut along both sides of the backbone. Remove the backbone and discard.
Flip the chicken over and press down on the breast of the chicken to flatten it.
Transfer the chicken skin-side up onto a rimmed baking sheet.
In a small bowl mix together the oil, garlic powder, onion powder, 1 tsp salt, and 1 tsp black pepper until well combined.
Pat the chicken dry with paper towels then rub the oil/spice mix all over the skin-side of the chicken.
Roast the chicken in the oven until the chicken is cooked through and the skin is crispy, about 50 minutes.
Take the chicken out of the oven and allow to rest for 15 minutes before serving.