Undefined method `haml' when rendering haml in Pony mail from scheduled job
require 'sinatra'
require 'haml'
require 'pony'

get "/execute_all/?" do
  execute_all_tests()
  Pony.mail :to => "recipients@email.com",
      :from => "do-not-reply@email.com",
      :subject => "Test results,
      :html_body => haml(:email_layout)

      redirect "/"

end

scheduler caught exception:
undefined method `haml' for main:Object

scheduler = Rufus::Scheduler.start_new
   scheduler.every '2h' do
      execute_all_tests()
      Pony.mail :to => "recipients@email.com",
          :from => "do-not-reply@email.com",
          :subject => "Test results,
          :html_body => haml(:email_layout)
   end