Steps
- Heat 300ml of milk until nearly boiling. Mix 50g of superfine sugar, 2 egg yolks, 1 teaspoon of vanilla extract, 1 tablespoon plus 1 teaspoon of all-purpose flour, and 1 tablespoon plus 1 teaspoon of cornstarch.
- Whisk in the hot milk, return to the pan, and stir over high heat for about 5 minutes, until thick and smooth. Cover the surface with plastic wrap, cool, and chill.
- Preheat the oven to 425°F / 220°C. Heat 125ml of milk, 100g of butter, and 125ml of water gently until melted, then bring to a rolling boil.
- Remove from the heat and beat in 140g of all-purpose flour, 1 pinch of sugar, and 1 pinch of salt until the dough leaves the pan sides. Spread on a plate to cool to lukewarm.
- Gradually beat in 4 beaten eggs, stopping when the paste drops slowly from a spoon. Pipe spaced 4in / 10cm lengths through a ⅜in / 1cm nozzle onto lined baking sheets.
- Bake one sheet at a time, reducing the oven to 400°F / 200°C when it goes in. Bake for 25 minutes, split the buns, and return upside-down for 5 minutes, until dry and golden; cool.
- Whip 300ml of heavy cream until thick. Beat the cold custard smooth, fold in the cream, and pipe into the cooled buns.
- Melt 100g of dark chocolate with 25g of butter in a bowl over barely simmering water. Remove from the heat and stir in 75ml of heavy cream and 1 tablespoon of sifted icing sugar.
- Let the glaze cool slightly, spread over the éclair tops, and leave to set.