Step 1

In a large enough bowl with the help of a Hand whisk, mix together sugar and egg yolk until slightly fluffy for about 1-2 minutes

Step 2

Mix in corn starch, flour, and vanilla with until thoroughly incorporated and have a smooth paste

Step 3

Bring milk to boil in a saucepan on medium heat then remove it as soon as it starts simmering. Make sure it is simmering but not crazy boiling, see m tips above

Step 4

Pour the warm milk over the egg yolk mixture slowly while whisking vigorously with a Hand whisk. This stage is effectively tempering the egg yolks and the mixture should already start to slightly thicken

Step 5

Pour the mixture back into the saucepan and cook on medium heat for a few minutes until it thickens. Concretely it is approximately 1 min after the first boil. It might get lumpy first, don't worry just keep whisking and the cream will get smooth and glossy. It's worth to keep a good quality (so that the milk won't burn in it) small/medium sized saucepan for making pastry cream only

Step 6

If in doubt, strain the pastry cream for a lump free, creamy end result

Step 7

Add in room temperature soft butter and mix with a Rubber spatula until completely incorporated. It is worth to add the butter in 3 stages and mix well after each addition.

Step 8

Pastry cream needs to completely cool before using it for in dessert. Place the cream into a shallow bowl and cover the entire surface with plastic wrap to avoid skin forming on top. Store in fridge

Step 9

Once cooled, you may need to whisk the pastry cream again to get a smooth texture. Make sure you do not over mix it as it can get runny. Give it a few whisk only until smooth. Use it to fill tarts, eclairs, cakes etc