How to put Bootstrap icon in ASP.NET button?

The HTML code is like this:

<a class="quick-btn" href="#">
   <i class="fa fa-plus-square fa-2x"></i>
   <span>New Job</span> 
</a> 

But I would like to use ASP.NET buttons instead of using HTML.
I found this solution, with using ASP.NET LinkButton.

<asp:LinkButton ID="lbtnNewJob" 
        runat="server" 
        CssClass="quick-btn" onclick="lbtnNewJob_Click">New <br />Job
        <span aria-hidden="true" class="fa fa-plus-square fa-2x"></span>
</asp:LinkButton>