Preheat oven to 325 degrees F. Line mini cupcake tin with paper liners. Set aside.
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
In a large bowl, whisk together egg, Zing™ Baking Blend, olive oil, and vanilla. Whisk until smooth.
In another bowl, combine hot water, cocoa powder, and espresso powder. Mix until smooth. Add milk and mix until incorporated. Add to egg mixture and whisk to combine.
Add dry flour mixture and whisk until batter is smooth. Batter will bubble slightly due to the baking soda. Let batter sit for 5 minutes to slightly thicken.
Divide batter among prepared cupcake liners. Bake for 15 minutes until cupcake tops spring back to touch. Allow to cool in tin for 3 minutes before transferring to wire rack to cool to room temperature.