These are just like little éclairs, just a touch sweeter to appeal to the young at heart. Reserve the leftover egg whites in the freezer for pavlova. Makes about 16.
1/2 cup granulated sugar
3 Tbsp. cornstarch
1/4 tsp. salt
4 large egg yolks
1-1/2 cups milk
2 tsp. vanilla extract
2 Tbsp. unsalted butter
1 cup water
1/2 cup unsalted butter
3/4 tsp. salt
1 cup all-purpose flour
4 eggs, beaten
3 oz. semisweet chocolate chips
1/3 cup heavy cream
To make the filling, whisk together the sugar, cornstarch, and salt in a medium saucepan until uniformly powdery. Add the yolks and whisk until smooth. Add 1/4 cup of the milk and whisk until combined, then whisk in the rest of the milk. Place the pan over medium heat. Cook, whisking constantly, until thickened like pudding, 7 to 10 minutes. Remove from the heat and add the butter, whisking until smooth. Stir in the vanilla extract. Transfer the custard to a bowl and cover with plastic wrap pressed up against the surface of the pudding to prevent a skin from forming. Poke a few holes in the plastic with the tip of a paring knife to let out steam. Chill until firm, at least two hours.
Preheat the oven to 425°F. Line two sheet pans with parchment paper.
In a medium saucepan, combine the water, butter, and salt, and bring to a boil. Remove the pan from the heat and add the flour. Stir the mixture with a wooden spoon (it will resemble mashed potatoes) and return the pan to medium heat. Stir vigorously to dry out the mixture until it is shiny with small beads of butter (3 to 4 minutes). Remove from the heat and transfer the mixture to a bowl to cool for 5 full minutes so the eggs don't scramble.
Reserve a tablespoon of beaten egg in a small bowl. Add the rest of the eggs in four parts to the dough, beating well after each addition with an electric mixer or a strong arm until fully incorporated. Spoon tablespoons of dough onto the prepared pans spaced at least two inches apart (you can also use a piping bag with a plain tip, but I’m much too lazy for that). Brush the tops with the reserved egg. Bake 25 to 30 minutes until the dough is puffed, golden-brown, and dried. Remove from the oven and poke a hole in the side of each puff with a toothpick to let the steam out while they cool.
When ready to assemble, make the glaze. Pour the chocolate chips into a small bowl. Heat the cream to a simmer and then pour it over the chocolate chips. Let stand for 1 minute and then stir (not too fast) with a spoon until the chocolate is melted and the mixture is completely smooth.
Carefully cut the puffs in half across the equators with a serrated knife, but keep the halves paired up. Fill the puffs with custard and replace the tops so the filling is hidden inside. You might be tempted to overfill them, but keep in mind that you need some airspace inside to keep the filling from squeezing out everywhere when you eat them. Spoon some chocolate glaze over the tops (if the ganache has solidified too much, heat it gently in the microwave for 10 to 20 seconds and stir until loosened). Refrigerate the puffs until the chocolate is set. Store in the refrigerator for 2 to 3 days.