Instructions

1. Pour the milk into a saucepan, add the vanilla extract, stir, and heat gently without bringing it to a boil.
   
2. In the meantime, place the egg yolks and sugar in a large bowl. Whisk well until the mixture becomes pale and creamy.
   
3. Sift in the flour and mix until smooth and fully combined.
   
4. Gradually pour the warm milk into the egg mixture, whisking constantly to prevent lumps.
   
5. Return the mixture to the saucepan and cook over low heat, whisking continuously. Do not let it boil. Cook until the cream thickens.
   
6. Remove from the heat and let it cool.