‘else’ is not recognized as an internal or external command, operable program or batch file

The else needs to be on the same “line” ^(a) as the if. Remove the new-line before the else like so:

if "zz"=="TRUE" (
    copy /a zz + /a ee=/a zz
) else (
    copy /a e + /a %TMP%=/a e
)

Please also note that "zz"=="TRUE" will never evaluate to true – I suspect you meant "%zz%"=="TRUE"?

^(a): This isn’t always a good description, though it’s what the Microsoft documents use. Same command may have been better, and putting ) and else on a different line breaks it into two commands.