I get this error: Method does not exist or incorrect signature: void addRecords()... when I try to call the method outside the trigger.

Full error message: 

AddRelatedRecord: execution of AfterInsert caused by: line 2, column 42: Method does not exist or incorrect signature: void addRecords() from the type AddRelatedRecordTriggerHandler

My TriggerHandler Class: 
public class AddRelatedRecordTriggerHandler {
    public static void addRecords(List<Opportunity> newOpportunities) {
        System.debug(newOpportunities);
        List<Opportunity> oppList = new List<Opportunity>();
        for (Account a : [SELECT Id, Name FROM Account
                          WHERE Id IN :newOpportunities AND
                          Id NOT IN (SELECT AccountId FROM Opportunity)]) {
                              oppList.add(new Opportunity(Name=a.Name + ' Opportunity',
                                                          StageName='Prospecting',
                                                          CloseDate=System.today().addMonths(1),
                                                          AccountId=a.Id));
                          }
        if (oppList.size() > 0) {
            insert oppList;
        }    
    }  
}

The trigger: 

trigger AddRelatedRecord on Account (after insert, after update) {
    AddRelatedRecordTriggerHandler().addRecords(Trigger.new);
}

I have tried every workaround am aware of to no avail... Please enlighten me...