Mix milk, sugar, salt, and vanilla in a saucepan over medium heat flame. When it boils, remove it from the heat.
In a medium bowl containing the corn flour. Start gradually adding a cup milk mixture with constant stirring until it thoroughly combines.
Transfer the flour mixture from the bowl to the rest of the milk mixture in the saucepan and put it on medium-low flame.
Continue stirring till the mixture thickens, then remove from the heat and let it cool down.
Pour the mixture in mold sprayed with cooking spray.
Cover the mold with plastic wrap and chill overnight. Serve and enjoy!