Preheat the oven to 350 degrees Fahrenheit.
Line a 9” springform pan with parchment paper and set aside.
In a large mixing bowl, combine the flour, cocoa powder, sugar, baking soda, baking powder, and salt. Mix with a whisk to evenly combine.
Add the oil, buttermilk, egg, vanilla, and warm water. Mix with a whisk until the ingredients are evenly combined.
Pour the batter into the lined springform pan.
Bake for 45 minutes or until a toothpick comes out clean. Set aside to cool.