This recipe for a classic chocolate cupcake is one to keep in the arsenal. It's the base for our Handwritten Valentine Cupcakes with Chocolate Glaze.
Preheat oven to 350 degrees. Line standard muffin tins with paper liners. Sift cocoa powder, flour, sugar, baking soda, baking powder, and salt into a large bowl. Add eggs, warm water, buttermilk, oil, and vanilla, and mix until smooth.
Divide batter among muffin cups, filling each 2/3 full. Bake until tops spring back when touched, about 20 minutes. Transfer cupcakes to wire racks, and let cool. Cupcakes will keep, covered, for up to 3 days.