\and command in \author tag

In the standard class the author is printed inside the environment tabular. Therefor the command \and is defined as:

\def\and{%                  % \begin{tabular}
  \end{tabular}%
  \hskip 1em \@plus.17fil%
  \begin{tabular}[t]{c}}%   % \end{tabular}

In your case you don't need an extra \and. You document class puts the author in a center environment. So you can use

\Author{John Doe \\
    \texttt{[email protected]} 
    %\and
    \\
    Jane Doe \\
    \texttt{[email protected]}
}

In article class \author command is internally set as a tabular and \and finishes one tabular and starts another so a list of authors becomes a list of tabulars.

this class just sets Author in a center environment and doesn't provide a replacement for \and. You could just use \\ or use

\renewcommand\and{\\[\baselineskip]}