Method

​1 Preheat the oven to 180°C/fan 160°C/gas mark 4. Grease the sides of a 20cm cake tin and line with greaseproof paper.

2 In a large mixing bowl, cream the butter in a large bowl until soft (using an electric hand whisk). Then add the sugar and beat until the mixture is light and fluffy. Gradually add the eggs to the mixture, beating well after each egg has been added.

3 Mix in the vanilla extract. Sift in the gluten-free flour and fold this into the mix. Add the milk and mix until everything is well combined.

4 Tip half of the cake mixture into another large bowl and into this bowl fold in the sifted cocoa powder. Place the cake mixtures into the prepared tin by alternating spoonfulls of the vanilla batter with the chocolate batter.

5 With a knife, gently draw swirls through the cake mixture to ‘marblise’ it. Don’t over mix or you won’t have that wonderful marble effect.

6 Bake in the oven for 45 minutes or until a skewer or a knife inserted into the middle comes out clean. Turn the cake out onto a wire rack and allow to cool before serving.