How to find and modify a puppet resource transaction?

I recently applied a puppet transaction:

puppet resource cron puppet-apply ensure=present user=root minute=30 command='/usr/bin/puppet apply $(puppet --configprint manifest)

To undo it, I simply went and edited my crontab

crontab -e ...

I'm sure that this is the "wrong" way to undo the transaction, but I couldn't find any metadata about the transaction inside of /etc/puppet/...

So - my question - is how can I find the and modify/decommision/delete puppet installed resources without having underlying knowledge of the resources themselves?

That is, where is the list of puppet created resources?

I always thought that puppet resources were defined in the site.pp file, but now I am finding that there are more than one way to modify the state of a system using, for example, by using the "puppet resource" tool.

If I have a misunderstanding of the way puppet works, please note that also - as Im somewhat new to it.