In a bowl, mix the flour, cocoa powder, baking soda, salt, and sugar. Set aside.

In another bowl, mix the olive oil, vanilla, and vinegar.

Mix the dry ingredients with the wet ingredients.

Preheat the oven to 350 F or 176 C.

Line your cupcake pan with cupcake liners.

Fill the cupcake liners ¾ full and bake for 15 to 18 minutes.

Let the cupcake cool after baking.

For the frosting, melt the butter in a pan and let it cool down.

Mix in the cocoa powder until smooth.

Alternatingly mix in the powdered sugar and milk until you get the consistency you want.

Mix in the vanilla.

If the frosting is too stiff, add a little milk or vanilla. If the frosting is too runny, add more powdered sugar.

Transfer the frosting to a piping bag with a piping tip of your choice.

Pipe out the frosting to the cupcakes.

Enjoy your cupcake!