Once the chocolate is melted, add cocoa powder and plant-based milk, and mix until combined.
2 tbsp unsweetened cocoa powder, 1/4 cup plant-based milk
Add the powdered sugar and vanilla extract to the chocolate mixture and stir until smooth.
1/4 cup powdered sugar, 1/2 tsp vanilla extract
Carefully fold the whipped aquafaba into the chocolate mixture until no white streaks remain.