Preheat oven to 350 degrees F. Line an 8 x 8 glass baking dish (or other small, shallow baking dish) with parchment paper. Allow an inch to overhang the sides.
In a food processor, combine all ingredients except chopped chocolate. Puree until completely smooth with no small bits of chickpea. Remove blade and carefully add chocolate and stir with a fork. Alternatively, empty batter into a bowl and stir in chocolate. I like the first option because it saves cleaning the extra dish :).
Pour batter into baking dish and spread to even thickness. Bake for 55-60 minutes. 55 if you want a very gooey blondie, 60 if you want it moist but a little more firm. Either way, allow to cool at least 30 minutes before enjoying. If you can wait an hour, it will be easier to slice.