The professional development of teachers is considered a central task of teacher training and therefore also for teaching technology education in an era of digitalization. The anchoring of technology and digital technologies is becoming a mandatory task in teaching especially due to curriculum requirements and an increasing importance of learning with and learning about digital technologies for dealing with everyday problems (Ministry for Schools and Education of the State of North Rhine-Westphalia (MSB NRW), 2021). The lack of emphasis on technology education in teacher training for primary school teachers in Germany presents a significant obstacle to the integration of technology education into the curriculum. Moreover, the individual decision on the extent to which technology education is addressed in the multi-perspective school subject 'Sachunterricht' leads to insufficient consideration. Furthermore, studies have demonstrated that the self-efficacy and subjectively assessed competencies of teachers have an impact on the inclusion of technology in 'Sachunterricht' (Möller, Tenberge & Ziemann, 1996). It is unclear how (prospective) teachers can acquire and test the necessary competencies to be able to carry out digital-technology and inclusive lessons in an educationally effective manner. To address this question, the present article employs a design-based research approach (Euler, 2014) to test and evaluate theoretical constructs in practice by prospective teachers.