Preheat the oven to 230°C (446°F)
Put the black beans in the bowl of your food processor and blend for a few moments.
Add the melted chocolate, the honey, the liquid coffee, and the melted coconut oil, and blend for 60-90 seconds.
Mix the ground rice and ground almonds, and add them to the batter in the bowl with the gluten free baking powder and salt.
Fold the mixture together thoroughly, to form a thick batter.
Line a 9 x 9 in. square tin with baking parchment and pour in the brownie batter.
Level out the batter and then bake in the oven for around 25 minutes, until a knife stuck in the centre comes out clean.
Allow to cool completely in the tin, then cut into 12-16 square pieces.