Preheat your oven to 400°F.
Place the turkey tenderloins in a baking dish and pour the melted butter over the tenderloins.
Sprinkle the salt, garlic powder, and black pepper on the turkey. Top it off with the rosemary.
Bake the tenderloins for about 40-45 minutes or until the thermometer reads 161°F.
Let rest for 10-15 minutes.