- Heat the butter and sugar in a saucepan over medium-high heat, stirring, until it caramelizes.
- Cool caramel slightly, then transfer to a mold.
- Let cool completely.
- Bring the 750 ml milk, sweetened condensed milk, sugar, star anise, and the cinnamon sticks to a boil, stirring occasionally.
- Grind the bread in a blender until powdered. Add cold milk, and blend until smooth. Make sure there are no lumps.
- Combine the cornstarch, vanilla, and ½ cup milk.
- Stir the bread mixture and cornstarch mixture into the hot milk. Simmer, stirring continuously, until the mixture becomes thick and smooth. Make sure it doesn't stick.
- Remove from the heat, and pour into the mold over the cooled caramel.
- Let cool to room temperature, then refrigerate for 3–4 hours.
- Serve cold.