Preheat the oven to 350 F and line a 9x9 square baking dish with parchment paper. Grind the pepitas in a coffee grinder or food processor into a coarse nut flour.
Make sure you have rinsed and drained your chickpeas well. Add all other blondie ingredients apart from the baking powder to the bowl of your food processor and blend until you have a smooth paste. Add more sweetener to taste. Add baking powder and mix batter thoroughly.
Pour the batter into a 9x9 square baking dish and smooth the top with a moistened spatula. Sprinkle pepitas on top, if using.
Bake blondies for 20 to 25 minutes or until the top starts to dry out and crack a bit and the edges start to pull away from the sides. Let cool and cut into squares. Serve with fudge sauce (recipe follows in next step)
Combine all the ingredients for the sauce in a small saucepan and bring to a boil, stirring well. Reduce temperature and let boil for a minute or so until a smooth sauce forms.