Religieuse, part 1: craquelin choux and vanilla pastry cream base

Craquelin: blend chilled salted butter, brown sugar and flour in a food processor until just combined.

Roll out between two sheets of parchment as thin as possible and freeze.

Choux: bring water, milk, salt, sugar and butter to a boil; off the heat, stir in the flour.

Return to medium-high heat, stirring constantly, until the mixture pulls away from the sides and a film forms on the bottom of the pan, about a minute.

Transfer to the mixer bowl and mix on low until slightly cooled, about two minutes.

Add the eggs, holding back a couple, and mix until combined; add one more egg until a soft peak forms, and the last if necessary. The paste should be neither hard nor too soft.

Pipe the bases with a 20 mm plain tip or a 12 mm open star tip, each base choux weighing 40 grams; makes 12 large.

Pipe small heads from the rest with a 10 to 12 mm plain tip, about half profiterole size.

Let the frozen craquelin thaw slightly, cut 55 mm (2 1/4 inch) discs for the large choux and 30 mm (1 1/4 inch) discs for the heads, and top each choux with a still-frozen disc; refreeze if it softens too much.

Bake the large choux five minutes at 450F.

Lower to 350F / 180C and bake 30 minutes more.

Turn off the oven and leave the puffs to dry with the door ajar for 15 minutes.

For the small puffs, reduce the baking time by 10 minutes.

Custard: bring milk, vanilla and a third of the sugar to a simmer; beat the yolks with the remaining sugar, then add flour and cornstarch.

When the milk boils, turn off the heat and whisk it gradually into the yolk mixture.

Return to the stove, bring to a boil and cook two minutes on medium-high, whisking constantly.

Off the heat, whisk in the butter.

For the chocolate filling, add chocolate to the hot custard.

Cool the custard in a baking tray lined with plastic wrap, with plastic wrap in contact with the top; at room temperature, refrigerate until completely chilled.