Preheat the oven to 425°F/220°C. Remove the neck and giblets from the turkey and dry it off with paper towels if needed so that it isn’t too slippery.
Place the turkey breast side down on a sturdy cutting board. Using kitchen/poultry shears, cut along one side of the backbone from the tail towards the neck.
Then use the shears to make another cut on the other side of the backbone in order to remove it. Save the backbone to make turkey stock later!
From the inside of the turkey, use a sharp knife to score the space in the center of the breast bone. This will help immensely in the next step.
Flip the turkey over so that you’re looking at the breast. Adjust the turkey legs so that they face outward, and press down on the turkey breast with force until you hear the breast bone cracking. Keep pressing until the turkey is flattened.
Now, flip over the legs, so that they are facing the sides. This will help protect the breast meat so that it doesn’t overcook. Tuck the wings behind the bird (as if the turkey is reclining on a warm beach).
Brush the turkey on both sides with olive oil or melted butter and season on all sides with your turkey seasoning. Place the turkey on a rack on a rimmed baking sheet and roast until done. The turkey is done when the internal temperature of the thickest part of the breast reaches 165°F/74°C.
Allow the turkey to rest for at least 15 minutes after you remove it from the oven.