Preheat the oven to 350 degrees Fahrenheit with a rack in the lower third of the oven. Line an 8-inch square baking pan with parchment paper. Grease the parchment paper.
Prepare flax eggs by mixing 2 tbsp of ground flaxseed meal with 6 tbsp of hot water. Let it sit for a minute to become sticky.
Drain and rinse black beans and puree in a food processer or blender along with flax eggs, vanilla extract, and canola oil.
In a separate bowl, combine all-purpose flour, cocoa powder, sugar, baking powder, salt, and ground coffee. Add the dry ingredients to the wets, then stir in chocolate chips.
Pour in batter and sprinkle on more chocolate chips directly on top of the brownies. Bake on the lower rack for about 40 minutes, until a toothpick inserted in the center comes out mostly clean. Cool the brownies in the pan on a baking rack.
Once the brownies are completely cool, lift the edges of the parchment paper and transfer the brownies to a cutting board. Use a sharp chef’s knife to cut the brownies into 16 squares.