Chocolate Buttermilk Cake

2/3 cup cocoa powder
1/4 cup boiling water, plus a little more if needed*
2 cups sugar
1 3/4 cups unbleached all-purpose flour
1 teaspoon baking powder
1/2 teaspoon baking soda
3/4 teaspoon kosher salt
1 cup buttermilk
2 eggs, lightly beaten
1/2 cup sour cream
1/2 cup vegetable oil
4 tablespoons butter, melted
1 teaspoon pure vanilla extract
1 cup semisweet chocolate chips, melted

Directions
1. Spray 5 small loaf pans with nonstick cooking spray and place on a baking sheet.* Preheat oven to 350 degrees. Combine cocoa powder with boiling water and stir until smooth. Set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine sugar, flour, baking powder, baking soda, and salt.
2. With the mixer turned off, add in buttermilk, sour cream, eggs, butter, and vanilla. Pour in cocoa powder and water mixture and mix everything to combine. Incorporate melted chocolate chips, and mix until everything is smooth. Pour into prepared pans. Bake for 45 minutes, or until cakes spring back when touched.
If you are baking this as a layer cake, butter 2 9 inch cake pans, lay in a round of parchment paper, butter, and dust with cocoa powder.