I'm looking for the name of this book.

It was a kid's spy vault book, with the left side being the book with various puzzles and activities that would earn you the combination to the right side, which was the vault.

The central gear was plastic with 8 buttons that could be slid to in or out, and once solved you could customize the combo for your own use.

I stored Girl Scout cookies in mine, which was a terrible choice as the vault was cardboard, and the cookies went bad.

The woman leading you through the book looked kinda like Cassandra from Perfect Dark, but I could be wrong about that. She also had a weakness for chocolate..?