Bring the milk and maple syrup to a low boil on stove (or heat in microwave). Results are better on stovetop.
Once the mixture is at a low boil, remove from heat and add 1/2 cup chocolate chips and allow to melt.
Preheat the oven to 350°F and line a 9"x9" baking dish with parchment paper or generously grease.
In a food processor, combine the rinsed black beans, nut butter, sugar, cacao powder, baking powder, salt, and vanilla. Pulse until it forms a paste.
Add the flour and melted chocolate mixture. Continue to pulse until it forms a thick smooth consistency. It will be thick but if you are worried, you can always add an extra spoonful of milk.
With a spatula, scrape into the baking dish and smooth out to spread the batter evenly through the dish.
Bake for 35 minutes, take care not to over bake as they will dry out.
Allow to cool for 15 minutes to prevent them from crumbling. Serve with milk or ice cream.