Melt the chocolate. You can do this two ways:
Double boiler: Add the chocolate chips to a heat-safe glass bowl and set it over a saucepan with 1–2 inches of water (make sure the bowl isn’t touching the water). Heat on low, stirring constantly, until the chocolate is fully melted and smooth.
Microwave: Microwave the chocolate in 30-second intervals, stirring between each round, until melted and smooth. Be careful not to overheat or burn it. Set aside to cool slightly.
Whip the aquafaba: Add the aquafaba to a very clean mixing bowl. Using a stand mixer or hand mixer, whip for 5–8 minutes until stiff peaks form. It should be thick enough that it stays in the bowl if you gently flip it upside down.
Blend the base: In a blender, combine the cocoa powder, tofu, salt, syrup, vanilla extract, and the melted chocolate chips. Blend until completely smooth.
Combine: Pour the blended chocolate mixture into the bowl with the whipped aquafaba and gently stir with a spatula until just combined.
Chill and serve. Divide the mousse evenly between 4 small bowls and refrigerate for at least 4 hours, or until fully set.
Top with a light sprinkle of crumbled graham crackers or fresh fruit, and enjoy!