\documentclass[%
a4paper,			
]{memoir}

\usepackage{cmbright}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}

\usepackage[clear-aux]{xsim}
\xsimsetup{
	load-style=layouts,
	exercise/template=centered,
	solution/print = false,	
	exercise/name = Aufgabe,
	blank/filled-style=\textcolor{Red}{#1},
	blank/line-minimum-length = 1cm,
	blank/scale = 1.5,
}		

\begin{document}
\begin{exercise}
Normal 	distance between header and text!
\end{exercise}

\begin{exercise}
\begin{enumerate}
	\item Greater distance between header and text!
\end{enumerate}
\end{exercise}
	
\end{document}