Preheat oven to 375° F. Line two cupcake pans with paper liners.
In a large mixing bowl, combine the water, cocoa powder, and espresso powder. Let them sit for 5 minutes so the chocolate flavor can deepen.
1 cup boiling water, 3/4 cup unsweetened cocoa powder, 1 teaspoon espresso powder
In a medium mixing bowl, whisk together the flour, sugar, baking soda, baking powder, and salt. Set aside.
2 cups all-purpose flour, 2 cups granulated sugar, 2 teaspoons baking soda, 1 teaspoon baking powder, 1/2 teaspoon salt
Whisk the milk, eggs, and oil into the cooled cocoa mixture. Stir in the flour mixture just until the batter is smooth.
1 cup milk, 2 large eggs , 1/2 cup vegetable oil
Fill the cupcake pan, so each cup is about 3/4 full.
Bake for 20-25 minutes until the tops spring back when pressed lightly in the center. Transfer to a cooling rack to cool completely.