Preheat the oven to 200°C (400°F). Line 2–3 baking trays with parchment paper.

Sift the flour into a bowl.

Place the butter, water, sugar, and salt in a medium-sized saucepan. Bring to a boil over high heat. As soon as the mixture comes to a boil (the butter will already have melted), remove the saucepan from the heat and add the flour.

Stir quickly with a wooden spoon until the mixture forms a ball and pulls away from the sides of the saucepan. Return the saucepan to low heat and continue stirring the mixture for another 2 minutes.

Turn off the heat and transfer the entire mixture to the bowl of a food processor or stand mixer. Process for 1 minute, then gradually add the eggs while the machine is running. Process or beat on high speed until the mixture is smooth, glossy, and homogeneous.

To shape the choux, you can use two teaspoons: use one to scoop up some of the dough and the other to push it onto the parchment paper. Alternatively, you can use a piping bag fitted with a round 1 cm (½-inch) nozzle. Do whatever works best for you.

Shape small choux, approximately 3 cm in diameter, and arrange them in rows on the baking trays.

Bake in the preheated oven for 15 minutes. Reduce the temperature to 175°C (350°F) and bake for another 15 minutes.

Remove the choux from the oven and, using a small knife or skewer, make a small hole in the side of each one to allow the steam to escape.

Return the choux to the turned-off oven with the door slightly ajar. You can place a wooden spoon in the door to keep it from closing completely. Leave them in the oven for 1 hour.

The choux should be crisp, not soft. Allow them to cool completely. At this stage, you can store them in a large airtight container or plastic bag in the refrigerator for up to a week.

If they become soft, you can place them back in a moderately low oven for a short while to crisp them up again.

Place the milk, heavy cream, and sugar in a saucepan over medium-high heat. As soon as the mixture is about to come to a boil, remove the saucepan from the heat.

Place the whole eggs and egg yolks in the bowl of a stand mixer or in a large bowl. Beat the eggs together with the corn starch until well combined. Add the vanilla.

Gradually add the hot milk mixture while continuously whisking with the mixer or by hand.

Once all the milk has been incorporated, return the mixture to the saucepan over low heat. Stir constantly until it begins to thicken. The best way to stir is with a whisk, so that the cream becomes beautifully smooth and velvety.

The pastry cream is ready when it begins to boil and has become thick and creamy.

Remove the saucepan from the heat and add the butter. Stir until the butter has melted and is fully incorporated.

Transfer the cream to a heatproof bowl. Cover with plastic wrap, pressing the wrap directly onto the surface of the cream. This prevents a skin from forming as the cream cools.

Allow the cream to cool slightly, then refrigerate until completely chilled. I usually make it the day before, or early in the morning, and fill the choux in the afternoon.

Place the heavy cream in a small saucepan and bring it to a boil.

Break the chocolate into small pieces and place them in a heatproof bowl.

As soon as the cream comes to a boil, pour it over the chocolate. Let the mixture stand for 2–3 minutes so that the chocolate can melt.

Then stir with a spatula or whisk until the mixture is completely smooth and uniform. Add the liqueur and stir.

At this stage, you can store the chocolate sauce in the refrigerator for up to 2 weeks. To melt it again, gently warm it in a bain-marie or in the microwave.

Assemble the profiteroles

Whisk the pastry cream with a whisk until light and fluffy.

You now have two options. You can fill the choux by placing the pastry cream in a piping bag fitted with a special filling nozzle.

Alternatively, you can use a small knife to make an opening in the middle of each choux (being careful not to cut it completely in half) and fill it with a teaspoon.

Arrange the filled choux on a serving platter and pour the chocolate sauce over them.

Serve, and with the very first bite you’ll understand that all that effort was nothing more than an immense labor of love...