One of the main drivers of acting creatively is people's belief that they can do so. Yet, most of the previous work on creative self-concept takes a domain-general perspective, telling us little about whether domain-specific interventions or activities can build people's creative self-perception. This paper specifically considers the domain of screenwriting to investigate and enlighten the debate in the area. We analyze the impact of an intervention focused on the development of creative self-efficacy and creative personal identity in an undergraduate screenwriting course at the Griffith Film School, Griffith University, Australia. The intervention, scaffolded by a creative metacognitive framework was an integral part of the course and was delivered by a Creativity Coach. Our results suggest that enrolling in an intensive and elective screenwriting course which included targeted teaching and self-reflection about creativity and the creative process, significantly improved participants' creative personal identity (valuing creativity) and creative performance, with no effect on their creative self-efficacy. We discuss the theoretical and practical implications of our findings and provide recommendations for future research.