Programming and computational thinking (CT) have become important topics in elementary education and are being implemented by national curricula, extracurricular programs, and informal learning environments. Most related research and implementation is mainly focused on block-based programming (BBP). However, BBP can lead to bad programming habits and a later transition to text-based programming (TBP) has been shown to be difficult for students, as they can lose confidence and motivation. Thus, we developed a course to facilitate the transition from BBP to TBP and foster CT while also promoting motivation and students’ programming-related self-concept. We considered data from 27 fourth-grade students aged 9 to 10, who participated in the course as part of an extracurricular enrichment program. In a pre-/post-test design, we assessed CT and its cognitive correlates such as non-verbal visuospatial reasoning, verbal reasoning, arithmetic competencies as well as the student’s motivation and attitude towards programming. Results indicated improved students’ CT, arithmetic, and non-verbal visuospatial reasoning. Furthermore, the transition to TBP did not significantly reduce students’ motivation for programming. Taken together, these findings indicate that the developed intervention may be helpful to facilitate the transition from BBP to TBP while keeping the students motivated and fostering CT.