The butter, eggs and buttermilk should be at a warm room temperature before starting this recipe. Set the butter on the counter about 30-45 minutes before starting (longer if your kitchen is cold). For the eggs, you can place them in a bowl of warm water. The buttermilk can be measured out into a bowl and set on the counter 10 minutes before using.

Preheat the oven to 325 F. Line a muffin tin with cupcake liners.

Set the butter, sugar, vanilla and salt in the bowl of a stand mixer. You can also use a separate bowl and hand mixer, it will just take slightly longer. Turn the mixer on low speed and beat for 3-5 minutes, stopping halfway to scrape the edges and bottom of the bowl for even mixing. Stop when the mixture is well creamed; light and fluffy.

With the mixer on, add the eggs one at a time, allowing the machine to beat them in for 30 seconds before adding the second. Beat until the mixture is emulsified and smooth, this can take up to 5 minutes - stop the mixer and scrape down and around as needed.

Over the mixture, sift in the cocoa and the cake flour. Add the baking soda. Turn the mixer on low, and as it’s mixing, slowly pour in the buttermilk. Once incorporated, pour in the boiling hot water (also with the mixer on). Scrape down the bowl as needed to ensure a well-mixed cake batter.

Spoon the batter into the prepared cupcake liners, filing them ¾ full. I use a disher (or ice cream scoop) to do this to make it easier, the batter is quite thin. You may have enough leftover batter for one more cupcake to make a baker’s dozen.

Bake the cupcakes until the tops spring back, about 25 minutes. Out of the oven, remove from the pan and set on a cooling rack. Let cool completely before frosting.