Preheat the oven to 350°F. Line 2 standard 12 cup muffin pans with paper liners. I generally get 26 cupcakes, so if you have another pan you can make two more, or you can put paper liners sitting upright in a loaf pan and bake them off free-standing like that.

First prepare the coffee and keep it hot. If you are using instant coffee, add 1 tablespoon of instant coffee granules or 2 teaspoons of espresso powder to 1 cup of just boiled water and set it aside while you prepare the batter.

Combine dry ingredients. Use a fine mesh sieve to sift flour, cocoa powder, baking powder and baking soda into a large bowl. Add sugar and salt and whisk to blend very well so the ingredients are evenly combined, pressing out any lumps of brown sugar.

Combine wet ingredients. Add eggs, oil, sour cream and vanilla to a medium bowl and whisk to blend well. Use a spatula to make a well in the center of the dry ingredients, then pour in the wet ingredients. Mix with an electric handheld mixer on medium-low speed until blended. You can also mix it in the bowl of a stand mixer fitted with the whisk attachment on medium speed or mix by hand using a wire whisk starting in the center and slowly dragging the dry ingredients in from the sides to combine evenly with the wet ingredients. It will be thick and somewhat dry. Add the hot coffee gradually in two stages to minimize clumps forming and mix until evenly combined and the batter is smooth. The batter will be quite thin.