Preheat oven to 350 degrees Fahrenheit. Line a 12 cup cupcake pain with cupcake liners.
Combine flour, sugar, cocoa powder, baking powder, backing soda and salt in a medium bowl.
Combine milk, egg, oil and vanilla extract in another bowl.
Slowly add the wet ingredients into the dry until just combined.
Carefully add the hot coffee and stir to combine. The batter will be thin.
Divide the batter between the 12 cupcake liners. I like to use a large cookie scoop or an ice cream scoop for this.
Bake for 14-16 minutes until a cake tester/toothpick inserted into the middle of a cupcake comes out clean or with a few moist crumbs.
Let the cupcakes cool in the pan for about 5 minutes and then transfer to a wire rack to cool completely.