Preheat your oven to 350°F (175°C). Grease a 10x15-inch jelly roll pan well, and line the bottom with parchment paper, leaving an overhang on the two longer sides.

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

In a large bowl, combine sugar and vegetable oil. Beat together until well combined.

Gradually add buttermilk while mixing until just combined. Add the egg and vanilla extract, and beat until smooth.

Incorporate food coloring until the batter is a vibrant red.

In a small bowl, combine vinegar and baking soda from the dry ingredients until it fizzes. Mix this into the wet ingredients quickly.

Fold in the dry ingredients until just combined, being careful not to overmix.

Pour the batter into the prepared pan, spreading it evenly.

Bake for 12-15 minutes, or until a toothpick comes out clean. It should spring back when pressed.

Prepare a clean kitchen towel dusted with powdered sugar to prevent sticking.

Once baked, invert the cake onto the prepared towel and remove the parchment paper.

Roll the cake up in the towel from one of the shorter ends. Allow it to cool completely.

In a mixing bowl, beat together the softened cream cheese and butter until light and fluffy.

Gradually add powdered sugar, beating until smooth.

Mix in vanilla extract and a pinch of salt. Adjust sweetness to taste.

Once the cake is cool, unroll it carefully and spread the cream cheese filling evenly, leaving a small border.

Reroll the cake without the towel, wrap in plastic wrap, and chill in the fridge for at least 2 hours.

Trim the ends of the roulade and dust with powdered sugar before slicing.

Slice into 1-inch thick pieces and serve.