Preheat the oven to 350°F.
Grease a 15x10-inch jelly-roll pan.
Line the pan with wax paper.
Grease and flour the wax paper.
Sprinkle a thin cotton kitchen towel with powdered sugar and set it aside.
In a large mixing bowl, sift together the salt, baking powder, cocoa powder, and cake flour.
Set the dry mixture aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the eggs for 5 minutes, or until light and slightly thickened.
Slowly add the sugar and vegetable oil.
Beat until fully combined.
Add the buttermilk, vinegar, vanilla extract, and red food coloring.
Mix until evenly incorporated.
Add the sifted flour mixture.
Stir until just combined.
Spread the batter evenly into the prepared jelly-roll pan.
Bake for 13 to 15 minutes, or until the top of the cake springs back when lightly touched.
Immediately loosen the cake from the edges of the pan.
Carefully turn the cake onto the prepared powdered-sugar towel.
Gently peel off the wax paper.
Starting from the narrow end, roll the cake and towel together.
Place the rolled cake seam side down on a wire rack.
Allow the cake to cool completely.
To prepare the filling, place the cream cheese, sifted powdered sugar, softened butter or margarine, and vanilla extract in the bowl of a stand mixer fitted with the paddle attachment.
Beat until smooth and creamy.
Carefully unroll the cooled cake.
Spread the cream cheese filling evenly over the cake, leaving a small border around the edges.
Reroll the cake without the towel.
Wrap the cake roll tightly in plastic wrap.
Refrigerate for at least 1 hour.
Before serving, dust the top with powdered sugar.
Slice with a sharp knife and serve chilled or slightly softened.