Thaw the turkey in the fridge, breast side down, for 3 full days.
The,. the day it is to be prepared, thaw it out on the kitchen counter for about 2 hours.
Remove the outer packaging and the giblets inside.
Dry the turkey well by patting it with paper towels. Also use paper towels to dry out the inside of the turkey.
Placed a kitchen towel on the counter and a large cutting board on top of it. The towel is to steady the cutting board so it doesn't slip. Then, place the turkey on the cutting board, breast side down.
Use sharp poultry shears, and cut the backbone out of the turkey. Start at the tail of the turkey and cut up one side of the backbone. Then, cut on the other side of the backbone. Some bones may be a little tougher to cut through, so you may have to use both hands on the shears. The backbone can be discarded or used to make stock or gravy.
Then flip the turkey over onto a rimmed baking tray. Place both hands firmly in the center of the breast, pressing down forcefully to flatten the turkey. This took a few tries, and you will hear the rib bone breaking.
After the turkey is spatchcocked, season it well with 1 tsp of salt, rubbing it into the bird.
Then, make the spice yogurt rub by mixing the spices with the yogurt.
Rub the spiced yogurt mixture all over the turkey. Separate the skin from the breast and thighs and spread some of the spiced yogurt mixture under the skin of the turkey as well.
Melt the butter in a microwave safe dish by microwaving for 20 seconds. Then, use a pastry brush and the turkey with the melted butter.
Tuck the wings under the breast and pop the turkey into the oven that had been preheated to 400 degrees Fahrenheit.
Roast the turkey for 30 minutes at 400 degrees Fahrenheit (204°C). Then, baste the turkey with the pan drippings, rotated the tray the turkey is on, and drop the temperature to 375 degrees (190°C) for another 30 minutes. Baste the turkey at the end of the 30 minutes with the dripping fat and juices, and placed some foil over it. Then, rotate the turkey again and bump the temperature to 400 degrees Fahrenheit (204°C) for the last 10-20 minutes of cook time.
Use a poultry thermometer to make sure the deepest part of the breast registers at 150°F (66°C), and the thighs register at least 165°F (74°C).
Let the turkey rest for 20 to 30 more minutes. Then carve it and serve.