Preheat oven to 160C.
In a bowl, tip in the flour, sugar, baking soda, cocoa powder and salt.Mix well.
In another bowl, tip in the vegetable oil, buttermilk, hot water, vanilla and egg, in another bowl.
Add the wet ingredients to the dry ingredients and mix until well combined.
Pour the batter into the cupcake liners/moulds about half way.
Bake for 18-20 minutes, or until a toothpick inserted comes out clean.
Cool completely before doing the icing.