Vanilla Pastry Cream (French Crème Pâtissière à la Vanille)

Pastry cream - made by heating milk, sugar, eggs, starch, and a flavoring together - is a rich, thick, and creamy custard that's a versatile workhorse in the baker's kitchen. It's piped into cream puffs and éclairs, spread between the layers of a Boston cream pie, and used as the base filling in fruit tarts.

2 cups whole milk (455 g)
1 vanilla bean, split and scraped
4 oz (½ cup) granulated sugar, plain or toasted (115 g)
1 oz (3 Tbsp.) cornstarch (30 g)
¼ tsp. Diamond Crystal kosher salt (use half as much by volume for regular table salt)
2½ oz yolks from 4 large eggs, straight from the fridge (70 g)
1 oz (2 Tbsp.) unsalted butter, cut into ½" cubes (30 g)

Special Equipment:
2 qt stainless steel saucier
balloon whisk
fine-mesh strainer

In a 2 qt 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.

In a large bowl, set up an ice bath by partially filling it with a combination of cold water and ice. Set aside.

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.

Uncover infused milk and remove vanilla bean. While whisking continuously, slowly pour milk into egg yolk mixture in a thin stream, until all of it has been added.

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.

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.

When ready to use the pastry cream, whisk until smooth.

Makes 2½ cups.

Cook's Notes:

I prefer Tahitian vanilla beans for their light, fruity-floral flavour, but you can use any variety of vanilla bean. Plus, you can reserve the used vanilla bean for other applications.

Make-Ahead and Storage:  Pastry cream can be stored in an airtight container, with plastic wrap or buttered parchment paper placed directly on the surface, and refrigerated for up to 3 days.