What do you need?
- 250g butter, at room temperature, plus extra for greasing
- 250g plain flour, plus extra for dusting
- 250g caster sugar
- 5 eggs
- 7g baking powder
- 100g dark chocolate (72% cocoa content)
- 2 tbsp icing sugar
Preheat the oven to 180 °C; grease the Bundt tin (2L) with butter and dust it with some of the extra plain flour. Combine the butter, caster sugar and a pinch of salt in a large mixing bowl and beat until fluffy, about 10 minutes.
Beat the eggs into the mixture one at a time; sift the plain flour and baking powder over the bowl and gently fold in. When the mixture is cohesive, place a third of the batter in a separate bowl. Chop the chocolate into chunks and put it in a heat-resistant bowl. Fill a large bowl (or pan) with boiling water and suspend the bowl with chocolate pieces above it, making sure the bowl does not touch the surface of the water.
Let the chocolate melt, stirring occasionally until completely melted. Pour the chocolate into the bowl containing a third of the cake batter and combine until the batter is uniformly brown in colour. Pour about half of the white cake batter into the Bundt tin, covering the bottom of the tin. Top this with the chocolate batter.
Finally, pour the remaining white batter as the top layer. Take a metal skewer and swirl it through the batter in a zigzag motion to create a marbling effect.
Put the chocolate marble cake on the middle shelf of the oven. Lower the oven temperature to 170 °C and bake for about 70 minutes, until risen and golden brown or until a skewer inserted into the centre comes out clean. Remove the cake from the oven and let it cool. Just before serving, sprinkle with the icing sugar.