Preheat the Oven: Set your oven to 350°F (175°C) and grease a mini muffin tin to prevent sticking.
Mix the Dry Ingredients: In a large mixing bowl, blend the flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.
Add Wet Ingredients: Pour in the milk, vegetable oil, egg, and vanilla extract. Mix until the batter is smooth.
Incorporate Boiling Water: Carefully stir in the boiling water. This step helps create that marvelously moist texture.
Fill the Muffin Tin: Pour the batter into the mini muffin tin, filling each cup halfway.
Bake: Place in the oven for 10-12 minutes or until a toothpick inserted in the center comes out clean.
Cool and Serve: Let the cakes cool for a few minutes before serving. Enjoy!