Preheat the oven to 350 °F.
Thoroughly rinse and drain the black beans. Grind the flax seeds in a food processor or use store-bought ground flax seeds. In a small bowl, combine with 8 tablespoons of water and set aside to thicken for about 5 minutes.
Then make the batter: Process the oats in a food processor into flour. Then add the remaining ingredients (including the soaked flax seeds) except for the chocolate chips and the NuGo bar. Process until smooth. Use the pulse function and a tamper to push down the mixture.
Grease a 9 x 8 inches baking tray and transfer the batter into the baking tray. Stir in the chocolate chips and the chopped NuGo bar. Bake for 35 minutes. Let the brownies cool down for a while.
In the meantime, make the topping. Transfer the coconut whipped cream to a small bowl and stir in the matcha tea powder until the cream becomes light green. Also add a couple of drops of peppermint extract. In a small bowl, melt the dark chocolate in the microwave.
Evenly spread the coconut peppermint whipped cream on top of the brownies, add the chopped NuGo bar on top, and drizzle with the melted dark chocolate. Store them in the fridge for about 20 minutes before you serve them. Enjoy!