make sure the cron file has the correct permissions:
sudo chmod 644 <file_here>
sudo chown root:root <file_here>
make sure each field contains a user field:
* * * * * root cd /home/piegarden/Downloads && echo "hello world 2" > ./hello2.txt
make sure there is a new line at the end of the file
* * * * * root cd /home/piegarden/Downloads && echo "hello world 2" > ./hello2.txt
You can check logs to troubleshoot:
grep CRON /var/log/syslog