Homemade Chocolate Cupcake Recipe

To make the cupcakes:
0 Preheat the oven to 350°F.
2 Prep the cupcake tin by greasing each muffin cup or use cupcake liners. Set aside. 
3 Whisk dry ingredients together in a large mixing bowl.
4 Prepare a double boiler by adding 2-inches of water in a medium saucepan over high heat. Bring to a simmer, then reduce the heat to keep the water at a slow simmer.  Add a large glass or metal bowl over top, making sure the fit is snug and the bottom of the bowl does not touch the water. 
5 To the large glass or metal bowl over a double boiler, whisk together the butter and buttermilk until the butter is melted totally. Then, add the espresso powder (or instant coffee), eggs, and vanilla. Whisk to combine.
6 Carefully remove the bowl from the double boiler (the bowl will be hot, as will the steam that will come out of the saucepan when the bowl is removed). Pour the wet ingredients into the dry ingredients and whisk until smooth. Stir in the chocolate chips.
7 Scoop the batter into the cupcake tin, filling each cup approximately ⅔ full. 
8 Bake the cupcakes for 25 minutes, or until a toothpick comes out clean from the center of the cupcake. You can also check by lightly pressing on the center of the cupcake with your index finger. If the cupcake rebounds, it is done.
9 Let the cupcakes cool in the tin for 10 minutes before transferring to a cooling rack. Let cool completely before frosting.   
To make the frosting:
10 Add all of the ingredients to a stand mixer with a whisk attachment.
12 Starting on low speed, blend the ingredients until combined.
13 Increase to medium-high speed and blend until smooth.
14 Use immediately to frost your cupcakes, or store in an airtight container in the fridge for up to 1 week.