This recipe yields a 10-layer Napoleon cake to save a little time and avoid the potential pitfalls of a taller confection. It’s a bit time-consuming to make, but the rewards of a soul-satisfying dessert are so worth it and comes out soft, moist and delicious. Start by preheating your oven to 375 degrees Fahrenheit. Prepare 2 large rimmed baking sheets, so you can bake the cake layers quicker, if you interchange them, putting one in the oven, rolling out the next layer and then immediately putting it into the oven as soon as the first layer bakes and so on.
When making the cake layer dough, it is easier to mix it on the counter by hand, using a knife to work the butter into the flour and then adding the liquid ingredients and mixing it by hand very quickly. You can also divide the ingredients in half and use a food processor to pulse the butter into the flour, then pour in the liquid ingredients and pulse just enough times for the dough to come together.
Combine the flour and salt on the counter or food processor. Add the cold butter, cut into chunks, into the flour and use a knife to work it into the flour, until there are pea-sized bits of butter throughout the dough. In a medium bowl or large mixing cup, whisk the water, vinegar, vodka, and beaten eggs until evenly mixed. The vinegar and the vodka helps to make the cake layers really tender and flaky. The vodka gives the dough more liquid and makes it easier to work with and roll out, but when the cake layers bake, the vodka will cookout, which makes the cake layers crisper. You won’t be able to taste the vinegar or vodka in the cake at all.
Make a well in the centre of the flour on the counter and pour in the liquid ingredients. Gently but quickly mix the dough, just until it comes together. Knead just a little, working the flour into the dough. Work as quickly as you can, so that the chunks of butter don’t completely melt into the dough. The chunks of butter will melt as the cake layers bake and will form air pockets in the cake layers and give them that wonderful thin, flaky, puffed texture.
Form the dough into a disc shape. Wrap the dough into parchment paper or aluminium foil and place it into the refrigerator. Chill for a few hours or overnight. Once baked, top your Napoleon cake with strawberies.
For the Pastry Layers;
- 2 ounces/4 tablespoons unsalted butter (softened)
- 1 tablespoon sugar
- 2 large egg whites (room temperature, stiffly beaten)
- 1 cup sour cream (room temperature)
- 1 tablespoon vodka
- 1 pinch salt
- 2 1/2 cups all-purpose flour
For the Custard Filling;
- 5 cups whole milk
- 10 large egg yolks (room temperature)
- 1 large egg white (room temperature)
- 2 1/2 cups sugar
- 6 tablespoons all-purpose flour
- 1 tablespoon vanilla extract
- 8 ounces/16 tablespoons unsalted butter
- In a large bowl, beat together 2 ounces butter and 1 tablespoon sugar together until creamy.
- Fold in 2 stiffly beaten egg whites, sour cream, vodka, and salt.
- Gently fold in the flour, a spoonful at a time, until the dough is soft and pliable. You might not need all of it.
- Wrap in plastic and chill for 1 to 2 hours to make it easier to roll out.
- When ready to bake, heat the oven to 375 F and butter a baking sheet pan and dust with flour.
- Divide the pastry dough into 10 pieces. Roll out each portion of dough directly on the prepared baking sheet into a very thin 8-inch circle.
- Bake each circle of pastry until golden brown, about 6 to 10 minutes. If dough blisters as it cooks, pierce them with a fork.
- As each layer is cooked, remove from the sheet pan and set aside to cool on a wire rack.
- Repeat until all dough pieces have been baked.
Make the Custard Filling;
- Pour the milk into a large saucepan and heat, but do not boil.
- In a large bowl, beat together the egg yolks, 1 egg white, and 2 1/2 cups sugar until creamy.
- Add 6 tablespoons flour and mix well.
- Pour this mixture into the warm (but not scalding hot) saucepan of milk, stirring initially with a whisk until smooth and then with a wooden spoon, constantly over low heat until thick and creamy.
- Add the vanilla and 8 ounces butter and stir until smooth.
- Remove from the heat and set aside to cool. Stir frequently as the mixture cools.
Assemble the Torte;
- Place one layer of the cooked dough in the bottom of an 8-inch springform pan and cover evenly with a layer of cooled custard filling.
- Continue to build up the cake in this way, layering the custard on top of the pastry, finishing with the 9th pastry layer.
- Crumble the 10th and final pastry, layer over the top of the torte. Refrigerate for 5 to 6 hours.
- When ready to serve, run a butter knife around the edges of the cake, remove the springform ring, and, using a cake lifter or two spatulas, carefully transfer to a serving platter.
- Use an electric knife to get nice, clean cuts and serve.