Preheat the oven to 180°C/160°fan/350°F/gas mark 4. Grease an approx 11.5 x 21.5 cm / 4.5 x 8.5 in loaf tin (2lb loaf tin) and line with a strip of baking parchment.

Place the cocoa powder in a large bowl and whisk in the boiling water to make a smooth paste. Set aside.

Place the silken tofu, milk, vanilla extract and vinegar in a blender and blitz until smooth. (I just put it all in a large jug and use a stick blender).

Place the plain flour, cornflour, baking powder, bicarbonate of soda, salt and sugar in a large bowl and whisk to combine.

Add the melted butter and oil to the dry ingredients and stir until no dry patches remain.

Gradually whisk the wet ingredients into the dry to form a smooth batter

Measure 500g of the batter (just under half) into the cocoa mixture and stir until smooth.

Spoon ⅓ of one of the colours into the prepared tin. Spoon ⅓ of the other colour on top (it doesn't have to be neat). Repeat this two more times so you end up with three layers of each colour.

Drag a skewer or knife through the batter a couple of times to swirl the colours together. Don't go mad here or you will just end up mixing them together rather than swirling; a couple of times is enough.

Bake the cake for 60-75 minutes until a skewer inserted into the centre comes out clean. You can loosely cover the top with tin foil towards the end of baking if it starts to get too dark.

Leave the cake to cool in the tin for 20 minutes then gently turn it out onto a wire rack and leave to cool completely before slicing.