Preheat the oven to 350F degrees. Line a muffin pan with muffin papers.
In a medium bowl whisk together the flour, cocoa powder, baking soda, baking powder & salt.
In a large bowl using an electric mixer, beat together the oil, sugar, egg, and vanilla extract (about 1 minutes). Carefully beat in the buttermilk.
Mix in the flour mixture about ½ at a time, turning off the mixer and scraping down the sides of the bowl in between.
With the mixer on low speed, carefully beat in the boiling water.
Spoon the batter into the prepared muffin pan, filling each about ⅔ full.
Bake for 16-19 minutes, or until the tops feel slightly firm to the touch and an inserted toothpick comes out clean.