Employing post-WIMP interfaces, i.e. user interfaces going beyond the traditional WIMP (Windows, Icons, Menu, Pointer) paradigm, often implies a more complex authoring process for applications. We present a novel authoring method and a corresponding tool that aims to enable developers to cope with the added level of complexity. Regarding the development as a process conducted on different layers, we introduce a specific layer for post-WIMP in addition to layers addressing implementation or traditional GUI elements. We discuss the concept of cross layer authoring that supports different author groups in the collaborative creation of post-WIMP applications permitting them working independently on their respective layer and contributing their specific skills. The concept comprises interactive visualization techniques that highlight connections between code, GUI and post-WIMP functionality. It allows for graphical inspection while transitioning smoothly between layers. A cross layer authoring tool has been implemented and was well received by UI developers during evaluation.