Create a div inside div with same class name

Question

I have the following structure of my HTML code:

<div id="bb-bookblock" class="bb-bookblock">
    <div class="bb-item">
        <div class="bb-custom-side">
            Hello
        </div>
        <div class="bb-custom-side">
            <button id="add">Click Here to add The page</button>    
        </div>
    </div>
    <div class="bb-item">
        <div class="bb-custom-side">
            <p>This is first page</p>
        </div>
        <div class="bb-custom-side">
            <p>Hello</p>
        </div>
    </div>
    <div class="bb-item">
        <div class="bb-custom-side">
            <p>This is second Page</p>
        </div>
        <div class="bb-custom-side">
            <p>This is last page</p>
        </div>
    </div>
</div>

When I click on button with id=add I want to create the a new div after the last bb-item div with same two div inside it having class name bb-custom-side.
I know how to create the div using createElement and it a class, but I don't know how to create the sub div inside that newly created div. Can I associate with the last child or similar concept?

So after click event I want my HTML to be something like this:

<div id="bb-bookblock" class="bb-bookblock">
    <div class="bb-item">
        <div class="bb-custom-side">
            Hello
        </div>
        <div class="bb-custom-side">
            <button id="add">Click Here to add The page</button>    
        </div>
    </div>
    <div class="bb-item">
        <div class="bb-custom-side">
            <p>This is first page</p>
        </div>
        <div class="bb-custom-side">
            <p>Hello</p>
        </div>
    </div>
    <div class="bb-item">
        <div class="bb-custom-side">
            <p>This is second Page</p>
        </div>
        <div class="bb-custom-side">
            <p>This is last page</p>
        </div>
    </div>
    <--Newly created div-->
    <div class="bb-item">
        <div class="bb-custom-side">
            new div
        </div>
        <div class="bb-custom-side">
            new div 2
        </div>
    </div>
</div>

Answer 1

Use clone() to create copy of div elements and append it to main div:

$("#add").click(function(){
    var clonedDiv = $(".bb-item:last").clone();
    clonedDiv = clonedDiv.find("div.bb-custom-side p").text("This is third Page");
    $("#bb-bookblock").append(clonedDiv);
});

DEMO FIDDLE

NOTE: I just updated text for last div (This is third Page). You have to put it in loop to increase number.