I like to make this dessert over the course of two days. The first day I'll leisurely make the pastry cream, and then I save the choux and frostings for the next day. Choux puffs are so easy to make, but you must give them ample time to puff in the oven. Pay attention to the temperature decrease during baking and don't open the oven door until they are fragrantly eggy and golden.
1cup/128g confectioners’ sugar - the finest you can findusually 10x
1teaspoonespresso powder dissolved in 2 teaspoons hot water
1/2teaspoonvanilla bean powder or 1 teaspoon vanilla extract
12-14roasted whole coffee beans
* Milk or heavy creamoptional
Pate a Choux
Preheat an oven to 425◦F/220◦C degrees. Line two baking sheets with parchment paper.
Combine water, butter, salt and sugar in a saucepan over medium heat. Bring to a boil and stir occasionally. At boil, remove from heat and sift in the flour, stirring to combine completely.
Return to heat and cook, stirring constantly until the batter dries slightly and begins to pull away from the sides of the pan.
Transfer to a bowl and stir with a wooden spoon 1 minute to cool slightly.
Add 1 egg. The batter will appear loose and shiny.
As you stir, the batter will become dry-looking like lightly buttered mashed potatoes. It is at this point that you will add in the next egg. Repeat until you have incorporated all the eggs.
Transfer batter to a pastry bag fitted with a large open tip (I piped directly from the bag opening without a tip). Pipe 12-14 choux about 1 inch-part in a baking sheet. Choux should be about 1 1/2 inches high about 1 1/2 inches wide. Pipe 12-14 smaller choux on the second sheet.
Using a clean finger dipped in hot water, gently press down on any tips that have formed on the top of choux when piping. You want them to retain their ball shape, but be smoothly curved on top.
Brush tops with egg wash (1 egg lightly beaten with pinch of salt)
Bake the choux at 425◦F/220◦C degrees until well-puffed and turning lightly golden in color, about 10 minutes. Lower the temperature to 350◦F/180◦C degrees and continue baking until well-colored and dry, about 20 minutes more. Remove to a rack and cool. Can be stored in an airtight container overnight.
Chocolate pastry cream
Dissolve cornstarch in 1/4 cup of milk. Combine the remaining milk with the sugar chocolate and cocoa in a saucepan over low heat. When chocolate is melted and thoroughly combined with the milk, bring the mixture to a boil; remove from heat.
Beat the whole egg, then the yolks into the cornstarch mixture. Pour 1/3 of boiling milk into the egg mixture, whisking constantly so that the eggs do not begin to cook. Return the remaining milk to boil. Pour in the hot egg mixture in a stream, continuing whisking. Continue whisking (this is important – you do not want the eggs to solidify/cook) until the cream thickens and comes to a boil. Remove from heat and beat in the butter, espresso powder and vanilla. Pour cream into a stainless steel/ceramic bowl. Press plastic wrap firmly against the surface. Chill immediately until completely cool. To fill pastry puffs, make a small slit in the sides or bottoms of the choux and pipe in pastry cream.
Stir together 1 tablespoon of the hot coffee and espresso powder in a small cup. In a separate bowl, whisk together the unsweet cocoa and confectioners’ sugar. Add the coffee/espresso mixture and whisk until thick. Add more coffee as needed until a thick, runny glaze is achieved. Add the gel food color if desired. Dip the tops of each filled choux puff into the glaze to the midline. Lift the choux from the glaze and allow the excess to fall back into the bowl. Place the dipped puffs on wax paper and allow them to dry until the glaze hardens, about 1 1/2 hours.
In a stand mixer fitted with the whisk attachment, mix together the butter and confectioners’ sugar. Begin mixing on low speed until crumbly, and then increase to high and beat for 3 minutes. Add the espresso mixture and vanilla and beat until light and fluffy. Transfer mixture to a piping bag fitted with a small star tip.
Place one large choux puff on a serving tray and pipe a buttercream star on top. Add a second smaller puff on top of the larger one and gently press down onto the buttercream star to secure. Pipe a buttercream star on top of the smaller puff and garnish the center with a whole coffee bean.
Store puffs in an airtight container in the refrigerator. Bring to room temperature before serving.
If you find the buttercream is too stiff for piping, you may add coffee, milk or heavy cream 1 tablespoon at a time until the mixture is piping consistency.