Yolk-Heavy Pastry Cream

Name: Yolk-Heavy Pastry Cream
Yield: enough to fill 12 buns or donuts
Cuisine: United States
Ingredients: 250 g whole milk; 60 g heavy cream; 1 vanilla bean, split and scraped (or 1 tsp vanilla paste); 90 g egg yolks (5 large hen yolks, or about 3 duck yolks); 65 g granulated sugar; 18 g cornstarch; 1 g fine sea salt; 35 g unsalted butter, cold, cubed

Also called crème pâtissière, vanilla custard filling

A very rich, yolk-forward vanilla pastry cream, set with cornstarch and finished with cold butter.

Makes: enough to fill 12 buns or donuts

Gluten-free Make ahead

Ingredients

Scale

Amounts are for the recipe. Sizes, times and temperatures in the method are not scaled.

250 g1 cupwhole milk
60 g¼ cupheavy cream
1vanilla bean, split and scraped (or 1 tsp vanilla paste)
90 gegg yolks (5 large hen yolks, or about 3 duck yolks)
65 g⅓ cupgranulated sugar
18 g2½ tbspcornstarch
1 g¼ tspfine sea salt
35 g2½ tbspunsalted butter, cold, cubed

Amounts worked out from the other system are rounded.

Method

Bring the milk (250 g1 cup), cream (60 g¼ cup) and vanilla to a bare simmer. Off the heat, cover and steep 15 minutes if using a bean.
Whisk the egg yolks (90 g) and sugar (65 g⅓ cup) until pale, then whisk in the cornstarch (18 g2½ tbsp) and salt (1 g¼ tsp) until completely smooth.
Pour about a third of the hot milk into the yolks in a thin stream, whisking constantly. Return everything to the pan.
Cook over medium heat, whisking without stopping and reaching into the corners of the pan. It will thicken abruptly and then look lumpy; keep whisking and it smooths out. Once it is thick, let it bubble for a full 60 seconds.
Off the heat, whisk in the butter (35 g2½ tbsp) a few cubes at a time, until glossy.
Strain through a fine sieve into a shallow dish and press plastic wrap directly onto the surface. Chill at least 4 hours, ideally overnight. Whisk smooth before using.

Notes

The full 60-second boil is not optional. It deactivates the amylase in the yolks, which otherwise breaks down the starch and turns the custard soupy after a few hours.
Duck yolks suit this well, giving a denser, more custardy set and a richer flavor. Substitute by weight, not count: a duck yolk is 25 to 30 g against a hen's 18 g.
Filling [[Melon Pan]]. Chill the custard hard. Either enclose 20 to 25 g in each bread ball before shaping (flatten the ball, spoon the custard in, then gather and pinch the seam tightly), or bake the buns plain and pipe it in through the base with a long tip. Filling before baking gives the better texture but risks a blowout: the seam must be sealed and the cookie shell must not reach the base. For a first attempt, fill after baking.

Used in Cold-Ferment Brioche Donuts