Preheat oven to 180C / 350F. Line a 12-cup muffin tin with cupcake liners. Line a second muffin tin with 10 cupcake liners. Set aside.
Sift together all-purpose (plain) flour, sugar, cocoa powder, baking soda, baking powder and salt into a large bowl. Whisk until thoroughly combined. Set aside.
Place eggs, oil, milk, vanilla extract and peppermint essence in another bowl.
Using an electric mixer, beat until combined. Add flour mixture to egg mixture. Beat until just combined.
Add hot coffee. Fold in gently.
Pour ¼ cup batter into each cupcake liner. Do not overfill.
Transfer muffin tins to oven. Bake for about 20-25 minutes or until a skewer inserted into the center of the cupcakes comes out clean.
Cool in pan for 10 minutes before transferring the cupcakes onto a wire rack to cool completely.