- 230 g butter, at room temperature
- 300 g sugar
- 2 free-range eggs
- 1 free-range egg yolk
- 1 T vanilla extract
- 3⁄4 cup sour cream
- 1⁄4 cup milk
- 260 g flour
- 40 g cornflour
- 2 1⁄2 t baking powder
- 1⁄2 t bicarbonate of soda
- For the chocolate marbling:
- 2 T milk
- 1 T butter
- 1 T sugar
- 2 T cocoa
- 1⁄4 t bicarbonate of soda
- For the peanut butter frosting:
- 1⁄4 cup smooth peanut butter
- 1⁄4 cup roasted white chocolate
Preheat the oven to 180°C and grease a 27 x 10 cm loaf tin. Using an electric beater, beat the butter and sugar until pale and fluffy. Add the eggs one at a time, beating well after each addition. Add the vanilla extract.
Mix the sour cream and milk and sift the dry ingredients into a separate bowl.
Add a third of the flour mixture to the egg mixture and mix until well combined. Add half the sour cream mixture and mix again until well combined. Add another third of the flour mixture and the remaining sour cream mixture and mix well, then add the last of the flour mixture. Mix until just combined and smooth. Do not overmix. Remove 1 1⁄2 cups of batter from the bowl and set aside for the chocolate marbling.
To make the chocolate marbling, combine the milk, butter and sugar and heat in the microwave, or in a saucepan, until the butter has melted. Whisk to dissolve the sugar. Add the remaining ingredients and stir to form a thick paste.
Add a few tablespoons of the reserved cake batter and stir well into the chocolate paste. Add the remaining reserved cake batter and fold until evenly incorporated and no light streaks remain.
Alternately spoon dollops of vanilla and chocolate cake batter into the greased loaf tin. Bake for 50–60 minutes, or until cooked through. Allow to cool.
To make the peanut butter frosting, beat the peanut butter and roasted white chocolate and use to ice the cake. Decorate with Chuckles if you like.
Cook's note: My gran was big on marble cakes and I would often take a slab to school, so this recipe has a nostalgic feeling for me. And who doesn’t love a chocolate-and-peanut butter combo?