Preheat the oven to 350°F. Lightly grease or line a baking sheet with parchment paper.

Combine the chickpeas, nut butter, maple syrup, vanilla extract, baking soda and baking powder in a food processor or blender and pulse until uniformly smooth.  Spoon the batter onto the baking sheet.

Add the chocolate chips (or cacao nibs) and mix together.

Spread the batter into a rectangle roughly 1 cm thick.

Sprinkle the remaining chocolate chips and sea salt if desired.

Bake for 15 minutes or until the top has nicely browned.

Let cool 5-10 minutes and then cut into squares.  If saving for later, let cool fully before storing, covered, in the fridge.