There are many iterations of devil's food cake. My version combines a light, fluffy cake, layered and frosted (it's an American cake, after all) with a chocolatey fudge. Both parts can be made a day ahead; keep the icing refrigerated, then re-whip to spreading consistency before assembling. Once frosted, this cake keeps well, and is even better the second day.
For the fudge frosting
200g dark chocolate chips (70 per cent)
200ml evaporated milk
100g castor sugar
100g light brown sugar
pinch of salt
½ tsp vanilla extract
fairy floss, to decorate
For the cake
3 tbsp plain yoghurt
120g unsalted butter (cubed)
150g castor sugar
150g light brown sugar
2 large eggs
2 tsp vanilla extract
270g plain flour
½ tsp fine salt
50g cocoa powder
1 tbsp white vinegar
1 tsp bicarbonate of soda
1. Begin by making the frosting, as it needs to sit and thicken. Place chocolate in a small heatproof bowl set over a small saucepan of simmering water. Once melted, set aside to cool to room temperature. Place the milk and sugars in a food processor and process for a few seconds before adding the melted chocolate, salt and vanilla. Process until thick and glossy (2 to 3 minutes). Scrape into a small bowl and set aside in a cool place until thick enough to spread (ideally for 1-1½ hours).
2. To make the cake, combine the milk and yoghurt in a small bowl and set aside. Preheat the oven to 190C (175C fan-forced). Grease and line two 20cm cake tins* and set aside.
3. Place the butter and sugars in the bowl of a cake mixer fitted with a paddle attachment and beat on medium-high speed until light and fluffy. Add the eggs, one at a time, beating well after each addition, then add the vanilla extract. Scrape the sides and bottom of the bowl with a rubber spatula to make sure the batter is well incorporated.
4. Sift the flour, salt and cocoa together. Then, over low speed, add one-third of it to the butter mixture, alternating with a third of the milk/yoghurt mixture until everything is combined. Mix the vinegar and bicarb of soda in a small bowl, then fold gently but thoroughly into the cake mix.
5. Divide the batter evenly between the two lined cake tins and smooth the tops with a spatula. Bake in the preheated oven for 20-25 minutes, until a skewer inserted into the centre comes out with just a few dry crumbs attached. Allow to cool for 15 minutes before inverting onto a cake rack to cool completely before icing.
6. Place one of the cakes (flat side down) onto a cake plate, anchored by a blob of the icing in the middle of the plate. Using a spatula, spread about a third of the fudge frosting evenly on top. Stack the second cake on top (flat side up) and apply a thin layer of the frosting on the top and sides of the cake so it forms a "base coat" that seals the cake and any stray crumbs.
7. Spread another layer of frosting over the top and sides, and smooth over. Decorate with fairy floss and ghoulish Halloween lollies on top for fun.
*Tip: Instead of using two 20cm cake tins, you could bake with one 23cm tin: just raise the baking time to 50 minutes and slice the cake in half when cool.