Mix dry ingredients in large bowl. Combine water, cocoa powder, and butter in heavy sauce pan, bring to a boil. Remove from heat, pour over dry ingredients, lightly mix together. Add milk and eggs. Blend well. Batter will be thin.
With a small 1 Tablespoon cookie scoop place one scoop of batter in each muffin cup. Bake in preheated oven for 10-12 minutes or until cakes bounce back when lightly touched. Remove from oven. If liners were not used let bites cool for about 10 minuets then using the tip of a knife gently remove from the pan and place on wire rack to cool completely.
In a medium sauce pan heat milk, butter and cocoa until bubbly, mix in sugar and vanilla until smooth. Add in nuts and blend until incorporated. Carefully spoon about a tablespoon of frosting over each bite and let frosting set if you can before eating!