Preheat oven to 190°C/375°F.
Place chickpeas, cashews, cocoa powder, baking soda, baking powder, vanilla extract, sea salt, and maple syrup in a blender and process until smooth. Pause and scrape the sides of the blender if needed.
Add flaxseed egg and stir to combine. The batter should be sticky and holds firmly together by now.
Gently fold into chocolate chips and a half of raspberries.
Pour the batter into a prepared square bake dish. Place the other half of raspberries on the top.
Place in the oven and bake for 25 minutes to reach a fudgy constistency. For more chewy brownies, bake for 35 minutes.
Remove from the oven and let the brownies sit for 20-30 minutes before cutting. For easier cutting, use a warm and lightly wet knife.