I got this recipe from the coconutlime blog http://coconutlime.blogspot.com/2007/01/cuba-libre-cupcakes.html
- Preheat oven to 350.
- Line or grease and flour 1 12 cupcake cupcake pan.
- In a small saucepan, heat butter, coca cola and rum to boiling. Remove from heat and allow to cool.
- Mix together lime juice and milk in a small bowl* or measuring cup and set aside.
- Meanwhile, whisk together cocoa, flour, sugar, baking soda, baking powder and salt.
- Add the cooled butter/coke mixture and beat until well combined.
- Add egg, beat then pour in the milk. Mix until combined. The batter will be rather thin.
- Fill each well 2/3 of the way full. Bake 20 minutes or until a toothpick comes out clean. Remove cupcakes to wire racks as soon as possible to cool.
- Frost with Chocolate Rum Cream Cheese Frosting when cool.
- Garnish with a wedge of lime.
- *This will sour the milk a bit. Do not worry if it looks slightly curdled.