Karpatka
An Original Recipe by Lorraine Elliott
Preparation time: 45 minutes plus cooling time
Cooking time: 60 minutes
Serves: 8 people
Pastry Cream Crème Mousseline Filling
- 100g/3.5ozs egg yolks (from 5 extra large eggs)
- 130g/4.6ozs caster or superfine sugar
- 100g/3.5ozs potato flour
- 600ml/20flozs whole full fat milk
- 3 teaspoons vanilla bean paste
- 200g/7ozs butter, room temperature, cubed
- 2 tablespoons caster or superfine sugar extra
- 2 tablespoons icing or powdered sugar
Choux Pastry Layers
- 130g/4.6flozs milk
- 100ml/3.5flozs water
- 100g/3.5ozs butter, chopped
- 10g/0.3ozs sugar
- 3g/0.2oz salt
- 130g/4.6ozs plain all purpose flour
- 4 large eggs, beaten together
Step 1 - First make the Pastry Cream as it needs time to cool down. Whisk the egg yolks with the sugar and potato flour in a large jug until the mixture is pale and there are no lumps. Place the milk and vanilla in a saucepan and almost bring to a boil. Temper the mixture by slowly pouring a cup-ful of the hot milk into the egg yolk mixture whisking it in. Gradually add more and stir. Then return the whole mixture to the saucepan and cook on low-medium heat stirring until it is thickened and smooth ensuring that the custard doesn't catch on the base or in the corners. Once it can coat the back of a spoon well, place in a wide, shallow tray and cover the top directly with cling film. Cool until it reaches room temperature around 20–22°C or 68–72°F. This takes a lot longer than you would think and a bit of time in the fridge definitely helps in this but don't refrigerate for a long time. If it becomes too cold, leave at room temperature for an hour and whip it up again before using it.
Step 2 -While it is cooling, preheat oven to 200C/400F/gas mark 6 and line 2 x 20cm/8inch round springform tins with parchment. Place the milk, water, butter, sugar and salt in a medium saucepan and bring to almost a boil. Remove from the heat and quickly mix in the flour with a flat bottomed wooden spoon or spatula. Place back on low heat and keep stirring vigorously until the dough pulls away from the edges-it should take around 2 minutes. Cool for 5 minutes.
Step 3 - Fit a mixer with a beater attachment and add the dough ball and start to beat and allow the heat to escape. Gradually pour in the beaten egg and keep beating until smooth and glossy. At this stage you can refrigerate this dough overnight or use straight away. Divide the dough among the two baking tins and create some ridges on the surface so that it isn't smooth-the more ripples and ridges the more it will resemble mountains. Bake for 28-30 minutes but do not open the oven during the first 26 minutes. Cool on a wire rack.
Step 4 - With a mixer fitted with a whisk attachment, whip the butter and the 2 tablespoons sugar together until it is white (you may need to scrape down the sides multiple times to ensure that the whole butter mix is whipped and white). Then add the crème patisserie or custard into this, 2 tablespoons at a time. Whisk until fluffy and smooth.
Step 5 - To assemble the cake, choose the least ridged choux half for the base. Place this half into a 20cm/8inch spring form tin and spray the sides with oil spray. Spoon the mousseline all over it and smooth it over with an angled spatula. Cover and refrigerate overnight. Place the other half of the choux pressing down gently to stick to the custard. Sift icing or powdered sugar over the top and serve.