Gwyneth Paltrow Chris Martin the grove apple martin Gwyneth Paltrow Chris Martin the grove apple martin

On Wednesday Gwyneth Paltrow had a book signing at Barnes and Noble at the Grove in Los Angeles, and we spotted hubby Chris Martin sneaking in a back entrance with the couple's two kids, Apple, 8, and Moses, 6. We can't believe how big they've gotten ... and how much Apple looks like mom and dad!

Gwyn is currently promoting her new cookbook It's All Good: Delicious, Easy Recipes that Will Make You Look Good and Feel Great, which focuses on cutting out carbohydrates and gluten.

"Life is about balance," Gwyn told the new issue of Self when promoting the book. "It's good to work in healthy food, whether it's five days a week or five meals a week. And if you're going to do it, it should be awesome food you're psyched to make. But never cut out the brownies or the wine."