Pre-heat oven to 350 degrees and line two baking sheets with silicone baking mats or spray with cooking spray.

Place black beans and cocoa powder in a high speed food processor and pulse until it reaches the consistency of sand, about 3-5 minutes.

Add espresso, peanut butter, syrup, vanilla, baking powder and salt then puree on high speed until ingredients are evenly incorporated, about 3-5 minutes, scraping down the sides of the machine once halfway through.

Remove the blade from food processor and scrape off any excess batter.

Using a small cookie scoop, scoop out batter evenly between two pans - should make two dozen cookies.

Sprinkle 1 teaspoon chopped walnuts on top of each cookie and gently press down into the batter.

Bake cookies until firm, about 12-14 minutes.