In a small saucepan, bring the milk to a gentle simmer. Remove from heat.
Meanwhile, in a medium heatproof bowl, whisk together the egg yolks, sugar and vanilla until the mixture is pale and is fully combined.
Temper the egg mixture: gradually add half the hot milk into the yolk mixture, one ladleful at a time, whisking continuously and quickly, to prevent the yolks from curdling.
Pour the mixture back into the saucepan. Cook over low heat, stirring constantly, making sure to scrape the bottom and sides of the pan. Use a wooden spoon or silicone spatula for this.
Keep cooking until custard thickens and coats the back of the spoon: trace a line across the back of the spoon with your fingertip. If the indentation remains, the custard is ready.
Strain the custard into a clean bowl. Cover with plastic wrap, pressing it down so it touches the custard. This will prevent a skin from forming on top. Refrigerate until ready to serve.
Serve warm or cold with fruits, pancakes, or cakes.