Take the ramekins. Grease them with butter and dust with sugar thoroughly inside the dish.
Preheat the oven to 200 Celsius.
Put a pan on the stove. Add butter to the pan and melt it on a medium flame.
When the butter melts, add flour and milk to it. Whisk it until it gets properly mixed and becomes thick.
Now take a glass bowl containing black chocolates.
Pour the milk, salt, and vanilla mixture onto the chocolate and whisk it properly until the chocolate gets melted.
Add egg yolk and whisk it properly when the mixture gets cooled.
Now take another ball, put two egg whites in it, and whisk it by gradually adding sugar until it gets thoroughly mixed.
Now add this egg white mixture into the chocolate mixture and combine it.
Now it's time to pour this shuffle batter into the ramekins.
Placed these ramekins in an oven and bake them for about 10 to 15 minutes until the top gets risen and becomes brown.
Now remove it from the oven and sprinkle cocoa powder over the soufflé.
The delicious soufflé is ready to serve.