How to handle async code in a backbone marionette initializer

I'm trying to put together backbone application using the marionette plugin, and am having some trouble getting initializers to work the way I expected them to. I have the following code:

var MyApp = new Backbone.Marionette.Application();

MyApp.addRegions({
    region1 : '#div1',
    region2 : '#div2'
});

MyApp.Resources = { };

MyApp.bind('initialize:before', function (options) {
    // display a modal dialog for app initialization
    options.initMessageId = noty({
        text : 'Initializing MyApp (this should only take a second or two)',
        layout : 'center',
        speed : 1,
        timeout : false,
        modal : true,
        closeOnSelfClick : false
    });
});

MyApp.addInitializer(function (options) {
    $.ajax({
        url: options.apiUrl + '/my-app-api-module',
        type: 'GET',
        contentType: 'application/json; charset=utf-8',
        success: function (results) {
            MyApp.Resources.urls = results;
            console.log(MyApp.Resources.urls); // <- THIS returns an object
        }
    });
});

MyApp.bind('initialize:after', function (options) {
    // initialization is done...close the modal dialog
    if (options.initMessageId) {
        $.noty.close(options.initMessageId);
    }

    if (Backbone.history) {
        Backbone.history.start();
    }

    console.log(MyApp.Resources.urls); // <- THIS returns 'undefined' BEFORE the console.log in the initializer above
});

Note in the code above that I have two console.log calls, one in the initializer, and one in the initialize:after handler. Both log the same object property. As you can see, what I'm experiencing is that the console.log call in the initialize:after handler is getting called before the one in the success handler of the initializer. I realize that this is because the initializer has an async call in it...what I need to know is, how can I make sure that all of the async code in my initializer(s) is complete before doing anything else in the application? Is there a good pattern for this? I've not found anything in the docs indicating how to handle this correctly.

Thanks.