1. Preheat oven to 350-degrees. Prepare muffin tins with 24 cupcake liners.
2. Bloom cocoa powder by whisking it into the hot coffee or hot water. Let it sit for 2 minutes.
3. In a large bowl, whisk together the sugar, flour, baking soda, baking powder, and salt.
4. Whisk eggs into the dry ingredients, followed by the buttermilk, oil, vanilla, and bloomed cocoa mixture.
5. Whisk together until well combined and smooth.
6. Carefully pour batter into your prepared cupcake liners, being sure not to overfill them.
7. Bake at 350-degrees for 20 minutes, or until the cupcakes are springy and a toothpick inserted into the middle of a cupcake comes out clean.
8. Allow the cupcakes to cool completely before you frost them.

For the Italian Meringue Vanilla Bean Buttercream:

1. Boil 1 cup of sugar with 1/4 cup of water over medium heat until it reaches 245-degrees.
2. In a large bowl, whip egg whites with a mixer on high until soft peaks form. (About 2 minutes)
3. Sprinkle 1/4 cup of sugar into the egg whites and keep whisking for another minute.
4. Once the sugar/water mixture has reached 245-degrees, slowly drizzle it into the whipped egg whites while you continue to whisk. Be very careful as it is hot.
5. Continue to whisk this mixture on high for 7 to 10 minutes.
6. Because you are adding hot water/sugar to the egg whites, the bowl will become warm. The next step is to add the butter, but we don’t want to do that while the mixture/bowl is too hot. Otherwise the butter will just make it a melty mess. So keep whisking until the bowl is no longer hot to the touch and the whipped egg white and sugar/water mixture is room temp.
7. Add the butter in large chunks.
8. Keep whisking on high until buttercream is well combined.
9. Scrape the bowl down well, and add your vanilla extract/vanilla paste.
10. Whisk until combined.