Originally posted by BakonGuy at Unity Answers: https://answers.unity.com/questions/775784/lerping-euler-angles-make-entire-spin.html, this script helps lerp around angles that potentially pass into the negatives, which would cause objects to spin rapidly.

AngleLerp.cs

//Properly Lerp between two angles
Vector3 AngleLerp(Vector3 StartAngle, Vector3 FinishAngle, float t)
{        
   float xLerp = Mathf.LerpAngle(StartAngle.x, FinishAngle.x, t);
   float yLerp = Mathf.LerpAngle(StartAngle.y, FinishAngle.y, t);
   float zLerp = Mathf.LerpAngle(StartAngle.z, FinishAngle.z, t);
   Vector3 Lerped = new Vector3(xLerp, yLerp, zLerp);
   return Lerped;
}