Vanilla Pastry Cream

Ingredients

• 2 cups (455 g) whole milk
• 1 vanilla bean, split and scraped
• 1/2 cup (115 g) granulated sugar, plain or toasted
• 3 tbsp (30 g) cornstarch
• 1/4 tsp salt (for table salt, use half as much by volume)
• 4 large egg yolks, straight from the fridge
• 2 tbsp unsalted butter (30 g), cut into 1/2-inch cubes

Steps

1. In a 2-quart stainless steel saucier, combine milk and scraped vanilla bean along with its seeds. Bring to a bare simmer over medium heat. Remove from heat, cover to prevent evaporation, and let steep for 30 minutes.
2. In a large bowl, set up an ice bath by partially filling it with a combination of cold water and ice. Set aside.
3. In a medium heatproof mixing bowl set on top of a dampened towel (this serves as a stable base), stir together sugar, cornstarch, and salt. Whisk in egg yolks until mixture is pale yellow, smooth, and fluffy, about 1 minute.
4. Uncover infused milk and remove vanilla bean (see note). While whisking continuously, slowly pour milk into egg yolk mixture in a thin stream, until all of it has been added.
5. Return the mixture to the same saucier. Cook over medium heat, whisking constantly until pastry cream begins to thicken, about 5 minutes. Once it thickens, continue to whisk, pausing every few seconds to check for bubbles, about 1 minute. When it begins to bubble, set a timer and continue whisking for 1 minute. This step is important to neutralize a starch-dissolving protein found in egg yolks.
6. Off-heat, whisk in butter until melted and thoroughly combined. Strain pastry cream through a fine-mesh sieve set over a heatproof medium bowl. Immediately place plastic wrap or buttered parchment paper directly on the surface of the cream to prevent a skin from forming. Transfer bowl to prepared ice bath to chill for 30 minutes, then refrigerate until cold, about 2 hours.
7. When ready to use the pastry cream, whisk until smooth.

Source

https://www.seriouseats.com/vanilla-pastry-cream-creme-patissiere