chown subfolders with current folder's owner and group

Solution 1:

You don't actually need to parse the output to remove the whitespace - you added that in your command! You can just format it as you like (with chown's colon syntax) in the first place:

$ stat -c "%U:%G" .
zanna:unicorns

So just pass that to chown with command substitution:

chown -R $(stat -c "%U:%G" .) .

Solution 2:

chown, like chmod, can use a reference:

chown [OPTION]... --reference=RFILE FILE...

Change the owner and/or group of each FILE to OWNER and/or GROUP.  With
--reference, change the owner and group of each FILE to those of RFILE.

So:

chown --reference=/some/folder -R /some/folder