Mongodb find in array and select that index

I have a Document setup like this:

Users

{
 _id : '',
 name : '',
 friends : [
   {
     'name' : '',
     'email' : '',
     'age' : ''
   }
 ]
}

I'm trying to select a single friend from within the friends array by email, while only returning that specific object.

Any suggestions how to do this?

Thanks!