1. Preheat the oven to 350 °F.2. In a bowl, mix the cocoa and dark chocolate. Pour in the boiling water and let it sit for 2 minutes. Whisk until smooth. Let it cool completely.3. In a mixer, cream the butter with the sugar and brown sugar until light. Add the eggs one at a time; beat in the vanilla and the cooled chocolate mixture.4. In another bowl, mix the flour, baking powder, and baking soda. Add this mixture to the chocolate mixture, alternating with the milk in 3 additions.5. Grease 24 individual muffin molds or line with paper muffin molds. Fill the molds 3/4 full. Bake for 20 minutes or until a toothpick comes out clean.6. Remove from the oven and let cool on a rack.