Preheat the oven to 350°F (175°C). Grease a 15 x 10-inch jelly-roll pan, then line it with wax paper. Grease and lightly flour the wax paper. On a clean cotton kitchen towel, sprinkle an even layer of powdered sugar and set aside.

In a large bowl, sift together the salt, baking powder, cocoa powder, and cake flour. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, beat the eggs for 5 minutes on medium speed, or until light and frothy. Gradually add the sugar and vegetable oil, beating until fully combined. Add the buttermilk, vinegar, vanilla extract, and red food coloring. Mix briefly until incorporated.

Gradually add the sifted dry ingredients to the wet mixture, stirring just until smooth and no dry streaks remain. Do not overmix.

Pour the batter into the prepared jelly-roll pan and spread it evenly using an offset spatula. Bake in the preheated oven for 13–15 minutes, or until the cake springs back when gently touched in the center.

Immediately loosen the edges of the cake and turn it out onto the prepared towel, powdered sugar side down. Carefully peel off the wax paper. Starting from one of the narrow ends, roll the cake and towel together into a spiral. Place the rolled cake seam side down on a wire rack and allow it to cool completely.

In a clean mixing bowl, beat the softened cream cheese, butter, powdered sugar, and vanilla extract on medium speed until smooth, light, and creamy.

Once the cake is fully cooled, gently unroll it. Spread the cream cheese filling evenly over the surface, leaving a small border around the edges. Carefully roll the cake up again—this time without the towel—into a tight log.

Wrap the cake roll in plastic wrap and refrigerate for at least 1 hour before serving. Just before serving, dust the top lightly with powdered sugar. Slice into even portions and serve chilled or at room temperature.