This is my current .cshtml file:

@using DotNetNuke.Web.DDRMenu;
@{var root = Model.Source.root;}


@helper RenderNodes(IList<MenuNode> nodes) {
if (nodes.Count > 0) {

<ul class="dnnmega">
@foreach (var node in nodes) {
var class_string = "";

if (node.Depth == 0)
{
class_string += " root";
}
else {
class_string += " category child-2";
}

if (node.Separator == true) {
class_string += " mmSeparator";
}

if (node.Selected == true)
{
class_string += " mmSelected";
}

if (node.Breadcrumb == true)
{
class_string += " mmBreadcrumb";
}

if (node.First == true)
{
class_string += " mmFirst";
}

if (node.Last == true)
{
class_string += " mmLast";
}

class_string = class_string.Trim();


<li class="@class_string">
@if (node.Enabled) {
<a href="@node.Url">
<span>@node.Text</span>
@if (node.LargeImage != null) {
<img src="@node.LargeImage" class="mmIcon" alt="@node.Text" title="@node.Text" />
}
</a>
} else {
<span>@node.Text</span>
if (node.LargeImage != null) {
<img src="@node.LargeImage" class="mmIcon" alt="@node.Text" title="@node.Text" />
}
}

@if (node.Children.Count > 0) {


// MEGA MENU CONDITION GOES HERE
<div class="megaborder">
<div class="TR">
<div class="TL">
</div>
</div>
<div class="MR">
<div class="ML">

@RenderNodes(node.Children)
</div>
</div>
<div class="BR">
<div class="BL">
</div>
</div>
</div>

// NON-MEGA MENU CONDITION GOES HERE
// <div class="nonmegaborder">
// @RenderNodes(node.Children)
// </div>
}
</li>
}
</ul>
}
}

@RenderNodes(root.Children)