Prague Cake is one of the stand out recipes from the award winning best-selling cookery book Mamushka. I bookmarked this recipe for well over a year and was looking for the perfect reason to bake this intricate cake. Lo and behold, my work had a charity bake sale so I made the chocolate cake with a condensed milk filling, slathered with chocolate ganache. You do need a little extra time to make this cake, it's not your ordinary chocolate sponge cake, but what it takes in time is rewarded in this gorgeous and unique chocolate cake.
5 eggs, fresh and cold
150g caster sugar
80g butter, melted and cooled, plus extra for greasing (optional)
30g cocoa powder
5 tablespoon caster sugar
50ml cognac (I used rum)
1 tablespoon water
4 egg yolks
4 tablespoons water
1 tablespoon cocoa powder
200g (7oz) slightly salted butter, softened
240g condensed milk
300g plain dark chocolate (70% cocoa solids), finely chopped
1) Place a medium metal bowl in the freezer, for making the filling later on.
2) Preheat the oven to 180C/350F/Gas Mark 4, and prep a 23cm (9inch) round spring form cake tin with a removable base by buttering it or lining it with baking parchment.
3) For the sponge, beat the eggs and sugar together in a bowl with an electric whisk for at least 5 minutes until very thick, pale and foamy. Trickle in the melted butter. Sift the flour and cocoa together and then gently fold into the batter with a spatula. Try not to knock any air out of the sponge - there is no raising agent, so air is all you've got to help it rise.
4) Pour the cake batter gently into the prepared tin and bake for 25 minutes. Test it by gently touching the top of with your finger - it should spring right back. Switch the oven off and leave the cake in the oven but with the door open.
5) Once the cake is cool, open the tin but not completely. To cut the cake into 3 equal discs, do the following place the base of the tin on something stable and tall (like a large jar) and push the cake out by two-thirds, then slice it horizontally with a bread knife. Push the cake up out of the tin a little more and cut across the cake again, making sure that the next disc is the same thickness as the first. You should end up with 3 discs of the same thickness.
6) To make the drizzle, heat the sugar, Cognac and measurement water in a small saucepan an boil briefly, then let it cool and drizzle over the sponges.
7) Next, make the filling by heating the egg yolks and measurement water in a glass bowl set over a pan of simmering water, whizzing constantly until the mixture turns thick and foamy. Stir in the cocoa powder and take off the heat.
8) Take the metal bowl out of the freezer and place the so dented butter in it, then beat it with an electric whisk. When it's starting to foam, trickle in the condensed milk, then gently fold in the cooled yolk mixture.
9) To make the ganache, pop the chocolate and butter into a glass bowl and set it over a pan of simmering water. Let it melt slowly, then give it a gentle stir once it looks almost melted - don't disturb it too much or it will go grainy.
10) Meanwhile, use the filling to sandwich the 3 sponge layers together, then spread the chocolate ganache on the top and down the sides of the cake.