Teacher creativity plays a central role in fostering creative learning environments. However, most evaluations of creativity training focus on performance outcomes and self-report measures rather than changes in underlying cognitive organisation. We investigated whether an eight-month certified teacher-training course based on the Scientific Creativity in Practice (SCIP) framework was associated with changes in Austrian secondary teachers’ creative performance, semantic organisation, and professional mindsets. Seventeen teachers completed pre- and post-training assessments, including the Alternative Uses Task, Verbal Fluency, Word-Sentence-Construction, Behavioural Forma Mentis associations with valence ratings, and written reflections. We assessed originality in the AUT with two independent AI-based systems. Semantic and affective changes were modelled through cognitive networks, mindset streams, and measures of emotional framing. At POST, teachers had higher AUT originality scores and generated largely different concepts than at PRE. They produced broader conceptual repertoires and larger semantic networks, although other structural changes differed across tasks. Affective changes were more modest. Positive valence predominated at both measurement points and became slightly more common, while negative valence declined. Separate PRE and POST mindset streams showed substantial pathway turnover but remained predominantly positive. These findings suggest that creativity training may support changes in how teachers organise and connect professional knowledge, and does not only impact how creatively they perform. Furthermore, our findings show that cognitive network analyses can complement traditional creativity assessments by revealing changes in semantic organisation and professional mindsets that remain invisible in performance scores alone.