The following commands can be used to create a new disk from an existing disk image snapshot.  A new VM can then be created from the new disk.  

$snapshot=Get-azsnapshot -resourcegroupname YOUR-RG-NAME -snapshotname SNAPSHOTNAME
$diskconfig=new-azdiskconfig -accounttype Premium_LRS -location $snapshot.location -sourceresourceid $snapshot.id -createoption copy
$disk=new-azdisk -disk $diskconfig -resourcegroupname YOUR-RG-NAME -diskname NEWDISKNAME