\documentclass[11pt,a4paper,english]{report}
\usepackage[T1]{fontenc}
\usepackage[latin1]{inputenc}
\usepackage{babel}
\usepackage{titlesec}
\usepackage{blindtext}
\parindent0em
\makeatletter
\newcommand*{\spelled}[1]{%
\expandafter\@spelled\csname c@#1\endcsname
}
\newcommand*{\@spelled}[1]{%
\ifcase#1\or{One}\or{Two}\or{Three}\or{Four}\or{Five}\or{Six}\or{Seven}\or{Eight}\or{Nine}\or{Ten}\else\@ctrerr\fi
}
\makeatother
% Setup for headings (titlesec)
\titleformat{\chapter}[display]
{\normalfont\Large\filcenter\bfseries\scshape}
{\LARGE\MakeUppercase{\chaptertitlename~\spelled{chapter}}}
{1pc}
{\Huge}
\begin{document}
\blinddocument
\end{document}