Looking for a book...

I am trying to remember a book with the storyline that Darcy and Mr. Collins were both hit by the same lightning bolt, and they switched bodies. And during the time that Darcy was in Collins' body, he became engaged to Lizzy, but they were switched back before a wedding. I cannot even remember the author's name. I remember it being very well written, great story. Any help is appreciated!
Thank you.