Ingredients
Custard Filling (Crème Pâtissière)
- 2 ½ cups milk
- 150 grams (¾ cup) granulated sugar, divided
- ½ teaspoon kosher salt
- 50 grams (5 tablespoons) cornstarch
- 4 large egg yolks
- 2 teaspoons pure vanilla extract or vanilla bean paste
Pâte à Choux (Choux Pastry)
- ¾ cup water
- 85 grams (6 tablespoons) unsalted butter, at room temperature
- ¼ teaspoon kosher salt
- 95 grams (¾ cup) all-purpose flour
- 3 large eggs
- Butter (for greasing pans)
- Parchment paper (for lining pans)
Crème Mousseline (Finishing Custard Filling)
- 200 grams (14 tablespoons) unsalted butter, at room temperature
- 25 grams (2 tablespoons) granulated sugar
For Topping
- Confectioners’ (powdered) sugar, for dusting
Instructions
- Prepare Crème Pâtissière (Custard Filling): In a saucepan, combine milk, half the granulated sugar, and salt. Heat over medium heat until just simmering, avoiding boiling. In a heatproof bowl, whisk together remaining sugar and cornstarch, then incorporate egg yolks until smooth. Temper the eggs by gradually whisking in about ½ cup of hot milk, then return the mixture to the saucepan with the remaining milk. Cook over medium-low heat, whisking constantly, until thickened (about 5-9 minutes). Remove from heat and whisk in vanilla. Transfer to a shallow container, cover surface with plastic wrap to prevent skin formation, and cool to room temperature.
- Make Pâte à Choux Dough: Preheat oven to 400°F (200°C). Grease two 9-inch springform pans and line bottoms with parchment paper circles. In a saucepan, combine water, butter, and salt; heat over medium until butter melts. Remove from heat, add all flour at once, and stir rapidly to combine. Return to medium-low heat and cook, stirring constantly, until dough forms a ball and leaves a white film on the bottom, about 8-10 minutes depending on your stovetop. Transfer to a mixer bowl; let cool about 10 minutes (still warm).
- Incorporate Eggs into Dough: With mixer running, add eggs one at a time, fully incorporating each before adding the next. The dough should become smooth, glossy, and fall off the paddle in a smooth V shape.
- Shape and Bake Pastry Layers: Divide dough evenly between prepared pans (about 210 grams each if weighing). Spread dough unevenly with the back of a spoon to create peaks and divots mimicking mountain terrain. Bake for 24-28 minutes until puffed and golden brown. Cool in pans for 10 minutes, then transfer to wire racks to cool completely. If using one pan, bake in two batches.
- Prepare Crème Mousseline (Finishing Custard): Ensure pastry cream and butter are both at room temperature (~70-75°F). In a stand mixer with whisk attachment, beat butter and sugar until pale and fluffy. Whisk the cooled crème pâtissière to loosen, then gradually add to butter mixture a few spoonfuls at a time on medium-low speed until fully incorporated. Beat for about 5 minutes until light and fluffy. Cover with plastic wrap pressed directly on surface if not assembling immediately.
- Assemble Karpatka: Place clean springform pan ring on serving plate, optionally lining ring with parchment paper for easier removal. Place one choux pastry layer (preferably less puffed) inside the ring. Spread the crème mousseline filling evenly over it. Top with the second choux pastry layer.
- Chill and Serve: Refrigerate assembled cake for at least 1 hour up to 3 hours to set filling. Remove ring and parchment paper, then dust the top generously with confectioners’ sugar before serving.
Notes
- Use fresh eggs and room temperature butter for best texture in fillings and dough.
- Careful when tempering eggs to avoid scrambling; add milk gradually and whisk vigorously.
- Ensure choux pastry dough forms a smooth ball and leaves a slight film on the pan bottom for ideal baking results.
- Creating peaks and divots in pâte à choux mimics mountain shapes, a signature look of Karpatka.
- Cool custard to room temperature before mixing with butter to achieve smooth, airy crème mousseline.
- If only one springform pan is available, bake choux pastry layers one at a time and cool completely before assembling.
- Use plastic wrap pressed on custard surfaces during cooling to prevent skin formation.
- Customize with vanilla bean paste for extra flavor depth.
- Prep Time: 1 hour 15 minutes
- Cook Time: 1 hour
- Category: Dessert
- Method: Baking
- Cuisine: Polish
