Preheat your oven to 350°F (175°C) and grease and flour the bundt cake pan thoroughly.
In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt until well combined.
In another bowl, combine the vegetable oil, buttermilk, eggs, and vanilla extract. Stir until blended.
Pour the wet ingredients into the dry ingredients and mix with an electric mixer on medium speed until combined.
Carefully stir in the boiling water; the batter will be very thin, which is normal.
Pour the batter into the prepared bundt pan and spread it evenly.
Bake in the preheated oven for 50-55 minutes or until a toothpick inserted into the center comes out clean.
Once baked, remove from the oven and allow the cake to cool in the pan for about 10-15 minutes before inverting onto a cooling rack.
Once cooled, dust with powdered sugar if desired before serving.