Éclairs are a staple of the French pastry case, elegant elongated poufs lovingly filled and dunked in ganache or fondant. You might think that means that they're one of those things that is just too fancy to make at home, or at least not a project you should tackle without having a day or two where you can afford to be leashed to your kitchen. And sure, éclairs can be fiddly to fill without crushing them.
But if you want all that éclair flavor without the hassle, the best way to go is with Resident Carolina Gelen's Éclair Cake, which harnesses the delicacy of the patisserie with good old-fashioned icebox cake. It's so easy that an 8-year-old can make it — and I should know, because I recently made it with an 8-year-old.
The 8-year-old in question, my partner's cousin, is a particularly precocious baker. He's attempted mirror glazes and started his own "bakery" with a group of fellow schoolmates, so I knew he'd be up for a project. What's lovely about the éclair cake, aside from the fact that it tastes very, very good, is that it harnesses the same techniques as a traditional éclair, but in a format that's a lot more forgiving.
The staple ingredient in this éclair cake, and indeed all éclairs, is pâte à choux, an eggy dough that you cook on the stove before finishing in a stand mixer. In regular éclairs and cream puffs, the dough rises in the oven, dries out, and forms a hollow pocket inside that can be filled with pastry cream or whipped cream or sweetened cream cheese. The éclair cake version uses that same dough piped into a square — you don't need to worry about it puffing up and forming a pocket, and if it doesn't rise well, who cares? You're going to layer it with pastry cream, top with another square of choux, and cover the whole thing in chocolate ganache. I promise it will taste good.
My 8-year-old friend noted that the most fun part of the process, aside from piping the pâte à choux into two careful squares that make the layers of the cake, was making chocolate ganache — you just melt chocolate into hot cream, stirring vigorously until it turns into a thick, icing-like mixture. His least favorite part? Waiting. Once you assemble the éclair cake you have to tuck it into the fridge overnight, and ideally for a whole day. Waiting is excruciating, particularly if you're 8, but it's the only way to get that crucial icebox cake texture. The pastry cream sets, the choux gets that crispy-gone-soggy feel, and the glossy chocolate layer tops it all off. It's worth the wait, but pro tip: let your assistant lick the ganache spoon to make it a little easier.
Recipe: Éclair Cake
- 1/2 cup (99 grams) granulated sugar
- 4 large egg yolks
- 1/3 cup (37 grams) cornstarch
- 1/4 teaspoon kosher salt
- 1 1/2 cups (341 grams) whole milk
- 1/2 cup (114 grams) heavy cream
- 1/2 vanilla bean (or 1/2 teaspoon vanilla extract)
- 2 tablespoons (29 grams) unsalted butter, cubed
Pâte à choux:
- 1/2 cup (114 grams) whole milk
- 1/4 cup (57 grams) unsalted butter
- 1 teaspoon (4 grams) fine sea salt
- 1 1/2 cups (180 grams) bread flour (or all-purpose flour)
- 5 large eggs (have an extra 2 on hand, just in case)
- 1 cup (227 grams) heavy cream
- 1/2 teaspoon kosher salt
- 1 cup (170 grams) chopped dark or semisweet chocolate (or chips)
- Make the pastry cream: Stir together the sugar, yolks, cornstarch, and salt in a heatproof bowl. Combine the milk, cream, and vanilla in a medium saucepan over medium heat and heat until hot. While whisking, slowly stream about half of the hot liquid in the yolk mixture. Pour this tempered yolk mixture into the pot with the rest of the milk mixture (you can pour through a fine-mesh sieve if you're worried about any cooked egg bits). Cook over low to medium-low heat for 4 to 8 minutes, stirring frequently, until bubbling and thickened like pudding. Turn off the heat, then mix in the butter. Strain through a fine-mesh sieve into a heatproof bowl, discarding any clumps caught in the sieve. Cover the pastry cream with plastic wrap to prevent a skin from forming. Refrigerate until cold. (This step can be done up to 2 days in advance.)
- Make the pâte à choux: In a medium saucepan, combine 1/2 cup (114 grams) of water, the milk, butter, and salt. Bring to boil over medium heat. Stir in all of the flour with a silicone spatula or wooden spoon. Reduce the heat to low and continue to cook, stirring constantly, until the mixture becomes sticky paste and there's a visible film of starch on the bottom of the pan, 2 to 3 minutes. Transfer the flour mixture to the bowl of a stand mixer fitted with a paddle attachment. Whisk the eggs in a large liquid measuring cup. With the mixer running on medium speed, add the eggs in slow, steady stream and continue mixing until totally incorporated, about 4 minutes total. Dip the paddle into the batter and lift it up — the batter should form a V shape that eventually breaks away from the batter in the bowl. If the dough is too stiff or pulls away too quickly, add another egg to loosen the consistency.
- Bake the pâte à choux: Heat the oven to 375°F. Get out an 8-inch square baking dish. Line a sheet pan with parchment paper. Using the baking dish as a guide, trace two squares with pencil on the parchment, then flip the parchment. Pipe or spread the choux evenly inside those two squares (about 320 grams of pâte à choux per square), leaving a 1/2-inch or so border for the pastry to expand in the oven and fill out the squares. Bake for 30 to 40 minutes, until puffed and golden brown. (Don't open the oven during the first 25 minutes, otherwise the choux will depuff.) Transfer the baked choux squares to a wire rack to cool completely.
- Make the ganache: In a medium saucepan over medium-low heat, bring the cream to a simmer. Remove from the heat and add the chocolate and salt. Wait a few minutes, then stir until the chocolate is silky smooth. Let cool until barely warm.
- Assemble the éclair cake: If needed, use a pair of scissors to trim the border of the choux squares so they can fit inside the baking dish. Place one choux square at the bottom of the baking dish. Stir the pastry cream to smooth out, then evenly spread that on top. Place the second choux square on top. Spread the chocolate ganache on top. Tightly cover the pan and refrigerate for 10 to 24 hours before slicing and serving.