\documentclass[]{book}
\usepackage[T1]{fontenc}
\usepackage[{{tex_lang}}]{babel}
\usepackage[utf8]{inputenc}
\usepackage{fancyhdr}
\usepackage{longtable}
\usepackage{booktabs}
\usepackage[a5paper, top=2cm,
left=2.5cm,bottom=1.5cm,right=1.5cm]{geometry}%A5
\setcounter{secnumdepth}{0}

\makeatletter

\newcommand{\HRule}{
  \paragraph{}
  \begin{center}
    *****
  \end{center}
  \paragraph{}
}


% Title
\renewcommand{\maketitle}{
  \thispagestyle{empty}
  \vspace*{\stretch{1}}

  \begin{center}
    {\Huge \@title   \\[5mm]}
  \end{center}
  \vspace*{\stretch{2}}

  \newpage
  \thispagestyle{empty}
  
  \pagebreak
  \newpage
  
  \thispagestyle{empty}
  \chapter*{}
  \vspace*{\stretch{1}}
  \begin{center}
%    {\Huge \@author \\[5mm]}
    {\Huge \@title   \\[5mm]}
%    {\huge \today   \\[5mm]}    
  \end{center}
  
%  \HRule

  \vspace*{\stretch{2}}

\begin{center}
{\large \@author}
\end{center}

                                
 \vspace*{\stretch{1}}

 \vspace*{\stretch{1}}
}
\pagebreak
\newpage
  \thispagestyle{empty}
\pagebreak
\newpage

% Headers
\pagestyle{fancyplain} 
\lhead[\fancyplain{}{}]{\fancyplain{}{}}
% Right header
\rhead[\fancyplain{}{}]{\fancyplain{}{}}
% Center header
\chead[\fancyplain{}{\rm\thepage}]{\fancyplain{}{\rm\thepage}}
% Footer
\cfoot{\fancyplain{}{}}
\makeatother

\title{ {{{title}}} }
\author{ {{{author}}} }

\begin{document}
\maketitle

{{{content}}}

\end{document}