jQuery select elements on 1st "level"

I want to select only the elements on the first "level".

Ex:

<div id="BaseElement">
  <p>My paragraph 0</p>
  <div>
    <span>My Span 0</span>
    <span>My Span 1</span>
  </div>
  <span>MySpan 2</span>
  <span>MySpan 3</span>
  <p>My paragraph 1</p>
</div>

Let's say that you got the BaseElement node.

var Element = $("div#BaseElement");

How do I fetch nodes from only the base element node?

$("div#BaseElement span")

should only result in getting MySpan 2 and MySpan 3.