Preheat oven to 350F. Grease and line a 8x8" pan with parchment paper, leaving edges out to easily remove the brownies after baking.
Pour butter into a large bowl of a standup mixer. Add the sugar and vanilla and mix. Add in eggs one at a time, beating well after each. Add cocoa and beat well. Whisk together the flour, baking powder and salt. Add to the mixture, beating well. Remove the bowl from the mixer and fold in the nuts. Pour into prepared pan. Bake for 2O-25 min or until done, don't over bake. Cool completely on a cooling rack.
For the frosting beat together the butter, cocoa, honey and vanilla in a medium bowl until blended. Slowly add the powdered sugar and milk, beat to desired consistency. Ice the cooled brownies and cut into 16 squares.
Nutrition calculation is an estimation only. If you need nutritional calculations for medical reasons, please use a source that you trust.