One method is to bake the dough at an extremely high temperature, approximately 425f(219c) for a short period of time to cause steam to form quickly and then lower the temperature to approximately 375f(190c) to finish the baking process. This causes the egg protein to coagulate and form a set structure.
The other method starts the baking process at a low temperature, approximately 300f(149c). Once the choux paste is in the oven, the temperature is raised immediately to a high temperature of approximately 450f(230c). Steam quickly forms, and the puffs rise. After approximately 10 - 15 minutes, the temperature is turned back down to 300f(149c) to dry the puffs and brown them. Starting at lower temperature gives the dough time to rise higher before the egg proteins actually set and a hard outer crust forms. This method is used to bake the Swans as great volume is obtained by starting the baking process at a lower temperature, which allows the puffs to rise higher before they become set and form a crust..
A high-protein/bread flour is used to give structure to the puffs, while whole eggs leaven and add structure, and egg whites are added for crispness and lightness.
A point to remember - choux paste must be baked until golden brown and crisp or else it will soften and collapse once it is cooled.
To make the Choux paste:
6 fl oz/3/4 cup/180 ml water
4 ozs/1/2 cup/115g unsalted butter
1/4 tsp salt
2 tsp sugar
5 ozs/1 cup/140 g bread flour
2 large eggs
2 large egg whites
Stabilized whipped cream
1/4 fl oz/1 1/2 tbsp/22 ml cold water
1/2 tsp unflavored gelatin
12 fl oz/1 1/2 cups/360 ml cold heavy cream
3 ozs/1/4 cup/100 gm confectioner's sugar, sifted(more for dusting)
1 1/2 tsp vanilla extract
To make the Choux paste:
In a medium saucepan, bring the water, butter, salt and sugar to a vigorous boil. Remove saucepan from heat. Add the flour all at once and stir mixture quickly with a wooden spoon. This will cause a ball of dough to form immediately. Continue to cook the mixture for approximately one minute until it forms a ball and pulls away from the sides of the pan. Remove the pan from the heat and allow the mixture to cool for 15 minutes to approximately 130f(54c) to prevent the eggs from cooking as they are added to the mixture.
Transfer the dough into the bowl of an electric mixer. Using the paddle attachment, mix the dough on low speed. Add 2 whole eggs, one at a time, blending well after adding each egg. Then add 2 egg whites, one at a time, blending well after each addition. The dough should hold its shape somewhat and should not be too loose. The color of the dough should be yellowish from the butter and eggs, and it should look glossy.
Creating the swan's body:
Preheat the oven to 300f(149c)
Place all but 3 ozs(1/3 cup, 105 g) of the dough into a pastry bag fitted with a large star tip (approximately 14 mm). Hold the pastry bag at 90 degrees to a parchment-lined sheet pan and pipe out a 2 1/2 inch(6 1/4 cm) long shell making an up and over motion. Pull back so that the end is tapered.
Continue to make approximately 12 more tapered shells leaving a space between each swan body.
Creating the swan's neck and head:
Place the remaining dough into a pastry bag fitted with a small round tip(approximately 1/8 inch, 3 mm). Pipe a small round ball(the head) and then continue to form a thin letter S (the neck) on a second sheet pan covered with parchment paper. Place the tip into the round ball(the head) and squeezing gently, quickly pull back to form the swan's beak. Repeat the procedure until there are as many swan necks as there are bodies (make extra in case of breakage).
Place the sheet pans in the oven at 300f(149c). Close the oven door and raise the oven temperature to 450f(230c). Bake for 10 - 15 minutes until well puffed. Turn the oven down to 300f(149c) and bake for another 15 - 20 minutes until crisp and browned. Cut open one of the puffs to see if it is dry inside. If not, continue baking.
Remove from the oven and with a small, sharp knife, poke a small hole into each puffs. This helps dry out the moist inside of each puff and allows them to cool faster.
Because the Swan necks are thinner, they need to be baked at a lower temperature of 375f(190c) for 8 - 10 minutes or until they are a pale brown and firm to the touch. Remove and allow to cool.
To Make the Filling:
In a small heatproof, sprinkle the gelatin over the water. Stir and allow it to soften for 5 minutes.
Melt the gelatin over a hot water bath until it is completely liquefied. Remove the gelatin from the heat and whisk 1/2 fl ozs(1 tbsp) heavy cream into the gelatin to cool.
In the bowl of an electric mixer, use the whip attachment to beat the remaining heavy cream until it forms soft peaks.
Gradually add the confectioners' sugar and then the melted gelatin and cream mixture along with the vanilla extract. Beat until stiff peaks form. Do not overbeat.
To assemble the Swans:
Cut each cooled swan body in half crosswise. Cut the top portion of the body lengthwise to form two wings. Leave the bottom half intact.
Using a pastry bag fitted with a large round or star tip, pipe the whipped cream into the bottom of the swan body. Gently insert a wing into the cream on either side.
Insert a neck into the cream. Repeat with the remaining swans.
Dust the swans with confectioners' sugar before serving.
Cream puff Swans should be refrigerated. They are best consumed the same day they are prepared, if they need to be stored overnight, do not insert the necks into the bodies until right before serving as refrigeration for over 4 hours softens them.. Leave the necks at room temperature covered in an airtight container.
Recipe adapted from Gail Sokol - About Professional Baking The Essentials.