Shift flour, salt, and cocoa and set aside.
Use a stand mixer to combine the sugar and oil and mix until well combined. Add in eggs one at a time.
Add food colouring and vanilla, and beat until well combined. Add flour mixture, alternating with buttermilk, and mix until fully combined.
In a small bowl, mix baking soda and vinegar well. Add it to the above batter, and beat for a few seconds.
Pour the batter into two prepared 6 inch pans or 8 inch pans. Bake at 175' C for 30-35 minutes.
Remove from oven and allow cakes to cool to room temperature.