Apex domains cannot have CNAME records.
Question and response
Question
dig awsdns-53.com. NS
Answer
awsdns-53.com. 5 NS g-ns-54.awsdns-53.com.
awsdns-53.com. 5 NS g-ns-1781.awsdns-53.com.
awsdns-53.com. 5 NS g-ns-1205.awsdns-53.com.
awsdns-53.com. 5 NS g-ns-629.awsdns-53.com.
Authority
The response has no authority records.
Additional
g-ns-54.awsdns-53.com. 5 A 205.251.192.54
g-ns-629.awsdns-53.com. 5 A 205.251.194.117
g-ns-1205.awsdns-53.com. 5 A 205.251.196.181
g-ns-1781.awsdns-53.com. 5 A 205.251.198.245
g-ns-54.awsdns-53.com. 5 AAAA 2600:9000:5300:3600:0:0:0:1
g-ns-629.awsdns-53.com. 5 AAAA 2600:9000:5302:7500:0:0:0:1
g-ns-1205.awsdns-53.com. 5 AAAA 2600:9000:5304:b500:0:0:0:1
g-ns-1781.awsdns-53.com. 5 AAAA 2600:9000:5306:f500:0:0:0:1
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0