prepare mini muffin tins either line with mini paper liners or use a baking spray that has flour in it. spray pans liberally. preheat oven to 350 degrees.
for cake:
mix sugar, flour, baking soda, and salt in large bowl. set aside.
combine water, cocoa powder, and butter in heavy sauce pan, bring to a boil. remove from heat, pour over dry ingredients, mix together until just combined. add buttermilk 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.
for frosting:
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! enjoy!
Notes:
if you don't have buttermilk on hand, you can make sour milk instead. add 1 teaspoon white vinegar to 1 cup milk and let it sit for a few minutes. add to recipe as directed.