Beat eggs with sugar, add flour , cocoa, baking soda, vanilla and milk and mix well. Add melted butter and stir gently. The mixture is distributed in mono - pre-greased and lined with paper baskets. Obtained 6 large or 12 medium muffins. Bake in preheated 180 C oven for 25-30 minutes. When you have finished with spiking with a toothpick to clean out.