Step 1

Cut the vanilla bean lengthwise then use a spoon or knife the scrape the seeds out. Add the milk and vanilla bean to a medium saucepan, heat then place over medium heat and bring to a boil.

Step 2

Immediately turn off the heat and set aside to infuse for 15 minutes.

Step 3

In a bowl, whisk the egg yolks and sugar until light and fluffy. Add the cornstarch and whisk vigorously until no lumps remain.

Step 4

Whisk in 1/4 cup of the hot milk mixture until incorporated. Whisk in the remaining hot milk mixture, reserving the saucepan.

Step 5

Pour the mixture through a strainer back into the saucepan. Cook over medium-high heat, whisking constantly, until thickened and slowly boiling.

Step 6

Remove from the heat and stir in the butter. Let cool slightly.

Step 7

Cover with plastic wrap, lightly pressing the plastic against the surface to prevent a skin from forming.

Step 8

Chill at least 2 hours or until ready to serve. The custard can be made up to 24 hours in advance. Refrigerate until 1 hour before using. I whipped some cream up and folded it into my chilled custard to lighten the filling up, this is now technically called diplomat cream.