Preheat oven to 200C/180C fan forced. Grease a 23cm springform cake pan and line the base with baking paper.
Cook the pasta in salted boiling water for 10 minutes or until al dente. Drain well and spread over a large tray to dry slightly. Arrange upright in the prepared pan to form a tight honeycomb pattern.
Meanwhile, melt the butter in a large frying pan over medium-high heat. When foaming, add the onion and bacon. Cook, stirring, for 3-4 minutes. Add the milk, cream and cream cheese, stirring until cheese is melted. Stir in the soup mix. Set aside to cool, stirring occasionally, for 10 minutes. Pour mixture over the rigatoni. Scatter with cheese.
Bake for 20-25 minutes or until golden. Rest for 5 minutes before cutting into slices to serve.
