Place your large bird on a large cutting board and pat dry with paper towels. Remove any extra turkey parts from the cavity and set them aside for turkey broth or turkey gravy.
Flip and cut out the backbone. Flip the entire turkey so the turkey breast side is down. Using sharp kitchen shears or poultry shears, cut up one side of the backbone, then the other. Remove the backbone completely and set it aside. (It makes incredible stock.)
Crack the breast bone. Flip the turkey so the breast is facing up. Press down firmly until you hear the breast bone crack and the rib bones flatten. This helps the spatchcock turkey cook evenly.
Dry brine the bird. Rub salt, pepper, and garlic powder all over the turkey skin and under it, too. If you prefer a wet brine, make sure to dry the skin thoroughly afterward. Place the bird uncovered in the fridge if you want extra crisp skin.
Make your compound butter by combining the butter, thyme, sage, and oregano.
Place the butter under the skin of the turkey.
Tuck the turkey wing tips under the skin to prevent over browning.
Roast at a higher temperature. Preheat the oven temperature to a nice high heat—usually around 425°F works beautifully.
Place the turkey on a roasting rack in a roasting pan or on a wire rack set inside a rimmed baking sheet. Brush with olive oil or melted butter.
Insert a thermometer like the RFX probe into the thickest part of the turkey breast or other type of thermometer to keep an eye on temperature.
Monitor the internal temperature. Spatchcock turkey cooks faster than a regular turkey, usually 6–10 minutes per lb turkey depending on your oven and bird size. Begin checking around the 45-minute mark with an instant-read thermometer. You're aiming for 160°F in the thickest part of the breast and 170–175°F in the thickest part of the thigh.
Rest before carving. Tent loosely with aluminum foil and let your delicious turkey rest for 20–30 minutes. This helps retain cups of liquid inside the lean breast meat and dark meat.