If you have your domain hosted in a server, you can create a html file with the following line on it:
<meta http-equiv="REFRESH" content="0;url=https://yourblog.blogspot.com/"></HEAD>
…. or (I like this one best), you can put your entire blog on a Iframe, so de URL will be your domain name:
<title>Your blog name</title><body leftmargin="0" topmargin="0" marginwidth="0" marginheight="0"><iframe src="https://yourblog.blogspot.com/" name="yourblogname" width="100%" height="100%" align="top" scrolling="auto"></iframe>
<style type="text/css">
<!--
body { overflow-y:hidden; overflow-x:hidden; }
//-->
</style>
Hope it helps.