Chocolate and vanilla cake batter, swirled together to make a deliciously simple cake! This recipe uses oil and real chocolate for a moist, rich flavour and only needs 2 eggs! (There’s also a vegan option for those who want to make it without butter or eggs). No self-raising flour or caster sugar needed either (just plain flour and granulated sugar) so it’s a quick and simple bake to make.
Whoever invented marble cake is a genius, you get the best of both worlds AND they somehow taste better marble together than they do separately? A simple vanilla batter is made and divided into two portions – one portion is left plain and the other is mixed with cocoa powder/chocolate. The two colours of batter are layered into a cake tin (usually a loaf tin or bundt tin) and swirled lightly with a knife – not enough to blend the flavours together, only just so they become entangled with one another so you get a bit of both flavour in each bite. I used to make marble cake with cocoa powder in the batter but since trying it out with real chocolate melted and swirled in, I haven’t gone back. The flavour is so much better when using melted choc here and, as the cake is so simple in its flavouring, I think it’s worth the extra bit of effort.
I use the reverse creaming method for this batter which means the dry ingredients are mixed with the fat first, and then the liquid ingredients are stirred in to get a smooth batter. I find this provides a nicely even, buttery crumb which is protected somewhat against overmixing so leads to a nicely spongey, moist cake. This is because the fat coats the flour granules somewhat preventing them from forming a gluten network once the liquids are added which in turn means you can mix this batter a little more aggressivly than you would a standard cake batter.
I’ve also tested this cake with vegan substitutions of vegan butter (block & tub margarine will both work – as long as they aren’t low fat). For the eggs I replaced them with blended silken tofu which I find works well in these denser cakey applications!
- 110g (1/2 cup) unsalted butter
- 185g (1 1/2 cups) plain white flour (all purpose flour)
- 20g (2 tbsp) cornflour (cornstarch), see notes for substitutes
- 1/2 tsp fine table salt
- 65g (2.25 ounces) dark chocolate (70% cocoa solids)
- 220g (1 cup) granulated sugar
- 1 tsp baking powder
- 1/4 tsp bicarbonate of soda (baking soda)
- 165g (2/3 cup) cow's milk, soy milk or oat milk
- 30g (2 tbsp) vegetable oil or neutral oil
- 2 tsp vanilla extract
- 2 medium UK eggs (large US eggs)
- 1 tsp vinegar (see notes) or lemon juice
- 2 tbsp brewed coffee or water
- Preheat the oven to 180°C (350°F) convection. Grease and line a 2lb loaf tin with a sling of baking paper and set aside.
- Place the butter into a medium pot and set over a medium-low heat. Allow to melt completely then remove from the heat.
- As the butter is melting, place the flour, cornflour and salt in a medium bowl and stir together to combine.
- Pour the hot melted butter into the flour mixture and stir together until you get a sandy, slightly bobbly mixture. Add the sugar, baking powder and bicarbonate of soda and mix together well. I like to use my fingertips here to rub all the ingredients together to ensure they're all mixed and to try to break up any large lumps.
- Take the pot (which should still be hot) you were using for melting the butter and place the chocolate into it, off the heat. Set aside and allow the residual heat of the pot to melt the chocolate. If it hasn't fully melted after ~5 minutes, place it over a low heat and stir until fully melted then remove from the heat. Set aside - we will come back to this later.
- Place the milk, oil, vanilla, eggs and vinegar into a jug or small bowl and whisk together - using a fork is fine. Pour this bit by bit into the sandy flour/butter mixture, stirring together between additions (using a whisk or large fork here helps) until all the liquid has been added and the batter is mostly smooth (there may be a few lumps here & there which is fine). It's okay to mix this batter a bit more than a standard cake batter so don't be afraid to give it a good mix with the whisk.
- Pour 300g (1 cup) of the batter into the pot of melted chocolate (OFF THE HEAT). Add the coffee (or water) and stir together - this is your chocolate batter! The batter which is left in the bowl is your vanilla batter.
- Layer the chocolate batter and vanilla batter into the lined loaf tin, alternating between the two flavours (I like to do this in 6 layers i.e. 3 layers of each flavour). You can also use a butter knife to gently swirl the batter together a few times - don't go overboard here or it'll just mix the batters rather than marbling them.
- Bake the cake for 50-60 minutes, covering with foil in the final 10 minutes if the cake is looking too brown. A toothpick inserted into the centre of the cake should come out clean.
- Allow the cake to cool in the tin for 10 minutes before tipping out onto a wire rack to cool completely. Once cooled, slice and enjoy!
- No cornflour? Use 20g (2 tbsp) of extra plain white flour here instead.
- Vinegar: use a neutral vinegar here, e.g. apple cider, white wine, distilled, malt, rice vinegar. DON'T use something flavoured like balsamic/sherry/red wine vinegar.
- Vegan (egg/dairy-free) version: instead of the eggs use 100g (1/3 cup + 1 tbsp) of blended silken tofu. In place of the butter use a vegan block margarine or tub margarine (NOT low fat). Use a non-dairy milk. Ensure the chocolate you're using is dairy free.