Combine all ingredients except for the chocolate chips in a food processor or high speed blender and blend, turning off and scraping down the sides when necessary, until the beans have broken down and the batter is smooth and pourable. Stir in half of the chocolate chips and pour the batter into the prepared 8x8.
Sprinkle the remaining chocolate chips over the top of the batter and pop into the oven. Bake for 30 minutes checking that the top has set, is slightly cracking and that the sides are starting to pull away