New Twiddle

components.my-component.js

import Ember from 'ember';
import f from '../templates/components/foo-bar';
import b from '../templates/components/foo-baz';

export default Ember.Component.extend({
  init() {
    this._super(...arguments);
    if (this.cond) {
      this.layout = f;
    } else {
      this.layout = b;
    }
  } 
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-component}}
{{my-component cond=true}}
{{outlet}}
<br>
<br>

templates.components.foo-bar.hbs

{{yield}}
foo

templates.components.foo-baz.hbs

{{yield}}
baz

templates.components.my-component.hbs

My component

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}