Pre heat oven to 350.
Butterfly the turkey breast open with a sharp knife. Place it skin side down on a cutting board, cover it with plastic wrap and then pound it out lightly with a meat mallet to flatten it a bit and make it an even thickness.
Remove the plastic wrap and sprinkle the breast with salt, pepper and garlic powder.
Spread the stuffing over the (non-skin) surface of the breast to within 3/4-inch from the edge. Roll it up as tightly as possible, finishing with the skin side up (towards you).
Using butcher's twine, tie up the turkey breast to keep its shape while roasting.
Rub the entire outer surface of the turkey with olive oil and season with salt, pepper and garlic powder. Place the stuffed turkey breast on a rimmed baking sheet lightly sprayed with a little olive oil spray.
Roast uncovered, until the stuffed turkey reaches an internal temperature of 165F, about 1 1/2 hours. (You may want to remove the turkey once it reaches 160 and allow it to reach 165 as it cools. This will avoid it from drying out).
If the top begins to get too brown, cover the turkey with aluminum foil.
Remove from the oven and let it sit, covered, for about 15 minutes or so before slicing. Snip off the butcher's twine, and serve.