Adjust block title height in tikzposter

Question

I want to reduce the height of block titles on my tikzposter. The tikzposterBlockstyles.tex file doesn't seem to mention an option for doing this, neither does the documentation. Is there a more low level way to achieving this? Thanks in advance.

Edit: MWE:

\documentclass[a0paper, landscape, 25pt, colspace=1cm, subcolspace=-1cm, blockverticalspace=1cm]{tikzposter} 
\title{Title}
\author{Person}
\institute{Institute}
%Choose Layout
\usetheme{Default}
\begin{document}
% Title block with title, author, logo, etc.
\maketitle[titletoblockverticalspace=1cm]
\block{Block Title}{Test}
\end{document}