compile layout

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  bodyFlag: false,
  actions: {
    swapBody() {
      let body = '';
      if(this.get('bodyFlag')) {
        body = '<h1>Some body!!!</h1>';
      } else {
        body = '<h1>Other body man!</h1>';
      }
      this.set('customBody', body);
    }
  }
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<button {{action "swapBody"}}>Swap body</button>
<br>
{{render-hbs body=customBody}}
<br>
<br>

render-hbs.component.js

import Ember from 'ember';
const { observer } = Ember;

export default Ember.Component.extend({
  layout: null,
  body: '',
  
  handleBodyChange() {
    const body = this.get('body');
    this.set('layout', Ember.HTMLBars.compile(body));
  },
  
  observeBody: observer('body', function() {
    Ember.run.scheduleOnce('sync', this, this.handleBodyChange);
  })
});

twiddle.json

{
  "version": "0.4.17",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}