Apex domains cannot have CNAME records.
Question and response
Question
dig moritzlaass.com. NS
Answer
moritzlaass.com. 1 NS ns-1638.awsdns-12.co.uk.
moritzlaass.com. 1 NS ns-607.awsdns-11.net.
moritzlaass.com. 1 NS ns-173.awsdns-21.com.
moritzlaass.com. 1 NS ns-1849.awsdns-39.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0