Grease 12-14 muffin tin hollows well with non-stick spray.
1. Filling: Heat the milk and cinnamon together in a saucepan until steam rises from the surface. Remove from the heat.
2. In a bowl, whisk the egg, egg yolks, sugar and corn flour together. Add a ladleful of milk to the egg mixture and beat. Add a second ladleful of milk and mix well.