Example of YAML file for Serverless framework to create SNS topics and export the name and the arn.

postConfirm.yml

Resources:
  SnsPostConfirm:
    Type: "AWS::SNS::Topic"
    Properties:
      TopicName: ${self:custom.snsTopicPostConfirm}
      DisplayName: Post Confirm User Cognito

Outputs:
  #Name of the topic to use it from other resources
  SnsPostConfirmNAME:
    Description: The NAME for the SnsPostConfirm Topic
    Value: ${self:custom.snsTopicPostConfirm}
    Export:
      Name: SnsPostConfirm-NAME-${opt:stage} # see Fn::ImportValue to use in other services and http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/outputs-section-structure.html for documentation on use.

  SnsPostConfirmARN:
    Description: The ARN for the SnsPostConfirm Topic
    Value:
      'Ref': "SnsPostConfirm"
    Export:
      Name: SnsPostConfirm-ARN-${opt:stage} # see Fn::ImportValue to use in other services and http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/outputs-section-structure.html for documentation on use.