Great post Jenn!
Nikki does the exact same thing as your Layla. She doesn't do it everyday though. I think it's kinda funny, except when I step on a kibble (ouch!). Oh, and I always add something to her kibble (yogurt, sauce, canned food, etc) so it's never dry.
My theory on this was maybe Nikki had some kibble in her mouth that did not have any yogurt or canned food on it, thus she spits it out. My Dad always tells me to "completely stir" her food so every kibble has something gooey on it, which usually does the trick. Still a mystery to me why Boxers do this though. Who knows?!? Hehe!! I think it's kinda cute, except for the cleaning part! :p