Step 1

Preheat the oven to 180C/350F/Gas Spray or butter a 13x9" Swiss roll pan, line with parchment paper, then spray again. Set aside.

Step 2

In a medium bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt.

Step 3

Using a handheld or stand mixer, beat the eggs until pale, and frothy. Add the oil and sugar, and beat until combined.

Step 4

Add the buttermilk, vinegar, red food colouring (start off with 1/4 teaspoon), and vanilla extract, and beat until combined. Add more colouring if desired. Gradually add the dry ingredients until just combined.

Step 5

Pour the batter into the prepared pan, and bake for 15 - 20 minutes, or until a toothpick inserted into the centre comes out clean.

Step 6

Immediately loosen the edges of the cake and invert the sponge onto a tea towel dusted with icing sugar. Peel away the paper, then gently roll the sponge and the towel up together.

Step 7

Cool completely on a wire rack, seam side down.

Step 8

Using a handheld or stand mixer fitted with the paddle attachment, beat the cream cheese, and butter until smooth. Add the icing sugar, and beat until smooth and fluffy.

Step 9

Gently unroll the cooled cake, and spread the filling over the inside of the sponge. Re-roll the sponge without the tea towel, wrap in clingfilm, and chill for at least 1 hour before serving.