The ability to write is central to students' success at school and beyond, and key to this success is the design and implementation of classroom learning experiences. Teachers' writing lessons are informed by their beliefs about learning, their writing content knowledge and pedagogical content knowledge. This knowledge supports their interpretation of curriculum documents and their ability to navigate resources for planning and implementing writing lessons. And for teachers who require further development of that content and pedagogical content knowledge, writing teaching becomes problematic. Media and government reports about the decline in writing performance in national and international assessments such as NAPLAN necessitates writing pedagogies research. Findings shared in this paper emerge from a larger project examining literacy demands in New South Wales classrooms across transition points of school. This paper examines two instances of classroom-based practice where students in two consecutive academic school years (Year 2 and 3) with two different teachers participated in a persuasive writing lesson about the same topic--Are cats better than dogs? Analysis of the pedagogical interactions and use of resources provide insights into teacher content knowledge, pedagogical approaches and the subsequent impact on student learning. These findings point to the need for better understanding about the demands on teachers to support students' development of genuine and empowering writing skills. Consequently, the paper argues for professional development that deepens teacher content and pedagogical content knowledge for pedagogies that can better support student writing.