In a saucepan over medium-high heat warm milk to just before the boiling point.
Remove from heat and stir in vanilla extract.
In a large bowl whisk egg yolks and sugar together until pale yellow.
Whisk in all-purpose flour.
Continue whisking and slowly pour the hot milk into the egg mixture. Do this a little at a time, so as not to curdle the eggs.
Pour mixture back into the saucepan and slowly bring it close to the boiling point, stirring constantly. Do not let it boil or the eggs will curdle and you will have a lumpy sauce.
When pudding has thickened, remove from heat and allow to cool 10 mins.
Place a piece of parchment paper on the surface of the sauce to prevent a skin from forming and cool to room temperature.
Chill in the refrigerator for 3 hours or until ready to serve.
Notes
Vanilla pastry cream can be used in a number of different ways. Drizzle over a cake or serve it with fresh fruit. You can also use it for the filling of a fruit tart or piped into pastries, like eclairs, cream puffs and donuts.If you have lumps and want a smoother pastry cream, pass the hot custard thru a sieve and then chill.