Preheat oven to 350°F (175°C). Grease and flour a 9-inch round pan.
In a large bowl, mix flour, cocoa powder, sugar, baking powder, baking soda, salt, and espresso powder.
In another bowl, combine milk, oil, eggs, and vanilla.
Slowly pour the wet ingredients into the dry ingredients, mixing until just combined.
Add the brewed coffee and mix until smooth.
Fold in the dark chocolate chips.
Pour batter into the prepared pan and bake for 35 minutes or until a toothpick comes out clean.
Let the cake cool in the pan for 10 minutes before transferring to a wire rack.