Preheat the oven to 350 degrees F. Spray a 9x5 loaf pan with non stick baking spray and line the long side of the pan with parchment paper. The parchment paper should make a sling and hang off the sides for the pan for easy removal.
In a medium bowl, sift together the cake flour, cocoa powder, baking soda, and baking powder. Whisk in the kosher salt. Set aside.
2 (250 g) cups Cake flour , ¼ (21 g) cup Unsweetened cocoa powder , 2 teaspoons Baking powder, ½ teaspoon Baking soda , ½ teaspoon Kosher salt
In a separate large mixing bowl, whisk together the eggs and granulated sugar until combined. The mixture should be thick. Next, add in the vegetable oil and melted butter, whisking until combined. Lastly, add the buttermilk, vanilla extract, and food coloring and whisk until smooth.
1 (200 g) cup Granulated sugar , 2 large Eggs, ¼ (57 g) cup Unsalted butter, ¼ (56 g) cup Vegetable oil , 1 teaspoon Red food gel , 1 tablespoon Vanilla extract , 1 teaspoon Distilled white vinegar , 1 (240 g) cup Buttermilk
Add half of the dry ingredients to the wet ingredients and whisk together until almost combined. Next, add in the rest of the dry ingredients. Lightly whisk the mixture together. Then, switch to a rubber spatula and gently fold in the rest of the dry ingredients until just combined. Be careful not to over mix and deflate the batter. The batter may look a little lumpy but it's ok.
Pour the batter into the prepared loaf pan and smooth with the back of a spoon or offset spatula.
Bake for 40 - 45 minutes or until a cake tester or wooden skewer inserted into the center comes out clean or with a few moist crumbs. The bread should have a dome shape and bounce back when lightly pressed.
Remove from the oven and allow the bread to cool in the pan on a wire rack for 15 minutes. Then, using the parchment overhang, lift the loaf out of the pan and place onto the cooling rack. Let the bread cool completely before glazing.