I have a Windows service that isn’t writing to the Application Event log under UserAccount. When the service is set to use AdminAccount, the Security log reports the following attributes:

Under UserAccount, the only privilege reported is SeImpersonatePrivilege.
Is there a security impersonation that I can implement to give the UserAccount the ability to write to the Application Event log?
I would prefer to use the UserAccount for this service rather than the AdminAccount.
I don’t think you should try to change user account privileges; if you want a specific user account to write to an event log, you need to make sure the user account you are running under has the required rights on the event logs ACLs. See e.g. Default ACLs on Windows Event Logs and How to set event log security locally or by using Group Policy in Windows Server 2003.