These are a slightly less sweet half batch, without the coffee, of the recipe at 101cookbooks.
You actually can't tell these are free of flour (gluten free I think?!) and you certainly can't tell they have beans. These are light and airy and everything you'd want in a brownie. And they are fabulous cold straight out of the fridge or freezer.
Spray large pyrex pan (12x7") with olive oil (or line with parchment if you want them to look pretty when you remove from the pan!).
Melt in glass bowl in microwave then stir until liquid:
1/2 C butter
2 oz dark chocolate (chopped)
Blitz in food processor until smooth:
1 C cooked black beans
1/4 C walnuts
1 tea vanilla extract and/or half vanilla bean pod
1/8 tea salt (or more if using coarse salt)
some of the melted chocolate from above
Beat 2 eggs and 1/2 C agave syrup (or slightly more, up to 2/3 C if you like it really sweet) with a hand mixer for about 1 minute.
Combine the chocolate mixture, bean mixture and egg mixture, stir until well combined.
Optional: reserve 1/4 C of egg mixture to drizzle on top and drag a knife through to make marbled texture.
Optional: stir in 1/4 C chopped walnuts for chunky nutty brownies.
Pour into oiled pan, bake at 325 for 40 minutes or more, until set in the middle. Let cool. Store in the freezer for chocolate emergencies :).