For the cupcakes
- Preheat oven to 140* C (280* F) Fan.
- Grease a 12 pan cupcake pan with butter and dust with flour.
- Whisk the boiling water, food coloring and buttermilk in a small bowl until completely combined and set aside.
- Sift the flour, baking soda and salt into a bowl.
- Beat the butter and sugar in a mixer, using the paddle attachment, until smooth and combined. Then add the vanilla.
- Lower the mixers speed and add 1/3 of the flour mixture and mix.
- Add 1/3 of the buttermilk mixture and mix.
- Repeat the same process another 2 times.
- Last, add the vinegar.
- Divide the cupcake batter evenly in the cupcake pan.
- Bake for 25-30 minutes.
- When ready, remove from oven. Set aside to cool in the cake pans.
- Turn out of pan and transfer to a wire rack until they cool completely.
For the chocolate buttercream
- Combine the caster sugar, butter, couverture, cocoa, milk and vanilla in a bowl until all of the ingredients are completely incorporated.
- Transfer icing to a piping bag and decorate cupcakes.