1. In a medium saucepan , combine 455 g whole milk .

2. Split a 1 vanilla bean lengthwise with a paring knife and scrape out the seeds with the back of the knife. Add both the seeds and pod to the milk.

3. Bring the milk to a simmer over medium heat, stirring occasionally. Once it begins to simmer, remove from heat, cover, and let steep for 30 minutes to infuse the vanilla flavor.

4. Meanwhile, in a medium bowl , whisk together 4 egg yolks (from large eggs, about 70g), 115 g granulated sugar , 30 g cornstarch , and 0.25 tsp kosher salt until smooth and pale yellow.

5. After the milk has steeped, remove the vanilla pod (you can rinse, dry, and save it for another use).

6. Reheat the milk until it just begins to simmer.

7. Slowly pour about half of the hot milk into the egg mixture while whisking constantly to temper the eggs and prevent them from curdling.

8. Pour the tempered egg mixture back into the saucepan with the remaining milk and cook over medium heat, whisking constantly, until the mixture thickens and begins to bubble, about 2-3 minutes .

9. Once the mixture starts to bubble, continue cooking for 1 minute more, whisking vigorously to ensure a smooth texture.

10. Remove from heat and whisk in 30 g unsalted butter (cut into 1/2-inch cubes) until fully incorporated and the pastry cream is smooth and glossy.

11. Strain the pastry cream through a fine-mesh sieve into a clean bowl to remove any lumps or bits of cooked egg.

12. Press a piece of plastic wrap directly onto the surface of the pastry cream to prevent a skin from forming.

13. Refrigerate until completely chilled and set, at least 2 hours or overnight.

14. Before using, whisk the chilled pastry cream vigorously to loosen it up and create a smooth consistency.