Combine 3 egg yolks, 1 whole egg, 85 grams of sugar, and 30 grams of cornstarch. Whisk until smooth and creamy, and then add 2 teaspoons of vanilla paste.
Bring 500 ml of milk to an almost boil and SLOWLY add to your egg mixture whisking while combining (not too vigorous whisking, otherwise it gets foamy).
Add the entire mixture back to the saucepan and whisk over medium-low heat (6-7 on induction) for about 5 minutes or until thick. It may look like it's not working, but suddenly it will.
Transfer the mixture to a bowl and add plastic wrap directly onto the cream. Chill for at least 2 hours.
Notes
Be patient while whisking over heat until thickened.
Chill the cream covered with plastic wrap to prevent skin formation.