1. Heat oven to 180℃/350℉. Grease a 20 cm loaf pan with oil/butter and line the bottom with parchment/butter paper.
2. In a large bowl cream butter and sugar together till smooth and light.
3. Add vanilla extract and eggs, one at a time, mixing well after each addition. Beat till fluffy and pale. Add milk and mix until creamy and smooth.
4. Sift in flour, cornflour, baking powder, and salt. Mix till just combined.
5. In another bowl mix cocoa powder and lukewarm milk till well combined. In to this add ¼ part of vanilla batter. Mix till a smooth batter is achieved.
6. Alternately fill the loaf pan with vanilla and chocolate batter. Tap the bottom of the loaf pan on your work surface to ensure that there aren’t any air bubbles.
7. Take a skewer and swirl it around the mixture in the tin a few times to create a marbled effect. 8. Bake the cake for 45-50 mins until a skewer inserted into the centre comes out clean. Turn out onto a wire rack after 5-10 minutes and leave to cool.
