Preheat oven on 350 and grease or lay parchment paper in pan.
In a saucepan thoroughly mix the butter, sugar, and cacao on medium heat until the butter's melted and it's smooth.
Remove from heat and stir in chia eggs and vanilla.
In a separate bowl mix the flours, baking powder, and baking soda, then add with the milk to the cacao mix, alternating each in slowly and beating until smooth.
Stir in the nuts and pour batter into the baking pan, cooking for 15-25 minutes until a toothpick inserted into the middle comes out smooth.
Cool for 1-2 hours before cutting into bars.
Cacao Frosting
Mix the powdered sugar and cacao then add softened butter, vanilla, and boiling filtered water.
Beat with electric mixer on medium until smooth then let sit until cooled before spreading.
Notes
Organic cocoa powder can be subbed for cacao if you prefer it.