Preheat the oven to 400 degrees F.
Clean the ramekins and coat with butter or oil. Heat the ramekins in the oven until you're done with the mixing.
In a medium bowl, add the semisweet chocolate and melt.
You can also melt the chocolate first then butter
Combine the butter with the melted chocolate until smooth.
Add the powdered sugar and combine.
Add one whole egg and one yolk egg to the mixture and mix.
Add the cocoa powder and mix.
Add flour and incorporate.
Pour the batter into the ramekins or baking tins.
Bake for about 12 minutes until the cake is firm on the edges and jiggle in the middle/center.
Sprinkle some powder sugar over the cake. You can serve with ice cream or any berries of your choice.
Enjoy!