Weigh out all ingredients and keep them ready.
In a saucepan, whisk together: Milk, Cream, Sugar, Cornflour. Heat on medium heat, whisking continuously, until the mixture thickens slightly (custard-like, not fully set).
Pour the hot mixture over the chopped chocolate. Let it sit for 30–60 seconds, then mix until the chocolate melts completely.
Add: Cold cubed salted butter, Vanilla extract. Mix until fully incorporated.
Blend using a hand blender until the crémeux is perfectly smooth, glossy, and emulsified.
Transfer to a container, place cling wrap directly on the surface, and refrigerate for a few hours until fully set. Use for cake decorating, frosting, piping, on cupcakes and lots more!
