Sourdough starter is one of those versatile and handy ingredients that every kitchen should have. It is delightful in so many forms, from a simple loaf to a chocolate cake.
So very easy to prepare, so wonderful in its simplicity, it requires only a bit of flour and water, and a spot of patience. However, during the feeding, a portion needs to be removed, and that portion becomes the discard. In reality, it does not need to be discarded; it can be used in many recipes, sweet and savoury, making it a marvellous and sustainable ingredient.
Adding the sourdough starter to cakes of any kind gives a wholly new level of flavour depth to them. Quite similar to a good, old-fashioned yoghurt cake flavour, only much softer and luscious.
To say that this type of cake is one of my favourites would be an understatement. Not only does it come together very quickly, it is also incredibly delicious, and keeps well for days. The slight touch of coffee enhances the natural flavours of cocoa and chocolate, and the humble sourdough starter makes the cake incredibly tender. It almost resembles a brownie cake, to be frank. And the frosting that adorns it is soft and smooth, and pairs perfectly with the fudge cake. It truly shows off how lovely and uncomplicated classic frostings are.
Ingredients
For the sourdough chocolate cake
120 grams plain flour, sifted
30 grams unsweetened dark cocoa powder, sifted
1 teaspoon instant espresso powder
1 teaspoon baking powder
¼ teaspoon baking soda
½ teaspoon salt
150 grams granulated sugar
100 grams ripe sourdough starter or discard
120 grams vanilla yoghurt
90 millilitres vegetable oil
2 teaspoons vanilla bean paste
1 large egg, room temperature
75 millilitres hot water
For the chocolate fudge frosting
50 grams milk chocolate
50 grams dark chocolate (at least 70% cocoa solids)
50 grams unsalted butter
40 millilitres whole milk
½ teaspoon vanilla bean paste
Preparation
Take a large bowl, add in the sourdough and the yoghurt, mix it gently together, and leave it in a warm spot for about 30 minutes, until bubbly and very fragrant. This batter may even expand a little as it stands. In another large bowl, whisk together the sifted flour, cocoa powder, espresso, baking powder, salt, and baking soda.
Tip in the granulated sugar, and whisk well again. Make a well in the centre of the dry ingredients and add in the sourdough starter and yoghurt, along with the oil, vanilla, and the egg. Whisk gently, but consistently, until a thick batter forms. At this point, it will almost resemble the initial stages of brownie batter. Pour in the hot water, and whisk until the cake batter becomes smooth and flowy.
Line a small round cake pan (16 cm) with baking parchment, pour in the batter and bake immediately in a preheated oven, at 180°C, for about 30-35 minutes. Check the cake for doneness with a toothpick, but make sure you check it even before the 30-minute mark, because all ovens bake slightly differently, and this cake should not be dry. Once baked, remove it from the oven, and let it cool down in the pan itself, as that is how it will be frosted.
While the cake is cooling, make the chocolate fudge frosting. Add both types of chocolate, butter, and milk into a saucepan, and let it all melt together nicely over medium heat. Remove from the stove, add in the vanilla, and let it cool down and thicken up slightly, about 5 minutes. Whisk well once again, and pour it all over the cooled cake. Let it stand at room temperature for about 30 minutes, so the frosting starts to set, and then transfer to the refrigerator for at least 4 hours, preferably overnight. Yields 10 servings.
