Iglesia de Santa María Tonantzintla is one of the Puebla region's great church interiors, a dense folk-baroque explosion of angels, fruit, flowers, saints, and indigenous-inflected ornament. The outside is comparatively restrained, which makes the interior hit harder.
It is outside Puebla's centre but well worth the detour, especially if paired with Cholula. Photography rules can vary, and the church is active, so keep the visit quiet and let your eyes adjust to the detail before moving on.