In a medium bowl combine cocoa and baking powder; mix to combine.
Add in boiling water; mix well with a wooden spoon to combine.
Add in the melted butter and vanilla; mix well.
Add in the sugar, mix well with a wooden spoon.
Stir in eggs with a wooden spoon; mix until combined.
Mix the flour with salt; add in the chocolate mixture; mix well to combine (batter will be a bit on the thin side).
Add/mix in mini chocolate chips or walnuts (or 1 cup of both!).
Using an ice cream scoop fill each of the muffin tins almost to the top.
Bake for 25-30 minutes or until muffins are done, don't over bake! (might take a little longer, depending on how full the muffin tins are with the batter).
Cool, drizzle glaze over or frost with buttercream frosting. (I made them as mini muffins and baked them at 350 for 13 minutes. I chopped up some (a scant 1/4 cup) semi-sweet chocolate chunks from Trader Joe's and mixed them in.--Nico)