Preheat the oven to 350 degrees and prepare two 8" pans with non-stick spray and parchment at the bottom.
In a medium bowl, whisk cake flour, salt, and cocoa - set aside.
In a stand mixer, fitted with a paddle attachment, mix sugar and canola oil until well combined.
Add in eggs one at a time.
Add food coloring and vanilla and mix until combined.
Add the flour mixture, alternating with the buttermilk. Mix until just combined.
In a small bowl, mix baking soda and vinegar. Stir it into batter until combined.
Pour batter into two prepared 8-inch pans. Bake for 30-35 minutes.
Once they are done, place the cakes on a cooling rack until they come to room temperature.
Once cooled, use a sharp knife to cut each cake into two layers.