I have created an ARM template for deploying resources into an Azure Resource Group. Is there any way I could use the same ARM template to perform automated "Baseline-Checks" in order to check if the resources have been changed in any way?
Are you just trying to determine if the state of the resources in Azure have "drifted" from the state declared in the template? If so you can use the what-if api and parse the results from that to see if something has changed.
If you want to prevent drift from occurring, you can lock the resources to prevent changes.
https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/lock-resources?tabs=json