In large mixing bowl prepare the brownie batter. Beat the butter until creamy. Add the sugars and cream until fluffy.

Add in the eggs and vanilla extract, mix until combined.

Add the flour, salt, and cocoa powder. Mix until fully combined and mixture is smooth. Will be thick.

Pour into the prepared baking dish. Use a rubber spatula to spread the batter into an even layer and smooth the top.

Bake for about 30-35 minutes until the brownies are baked through. Remove from the oven and allow the brownies to cool to room temperature.

Melt the chocolate and allow it to cool. It should still be stirrable but cool. Melt in the microwave heating in 30 second increments and stirring in between until all chocolate is melted.

Add white granulated sugar to the blender or processor and pulse until sugar is powder like and ultra fine.

In mixer cream the butter and the ultra fine sugar together. Pour in the cooled melted chocolate and mix until combined. Scrape the sides to ensure completely mixed.

Add in the vanilla extract and mix on low to combine.

Add in one egg, cold from the fridge. Mix on high speed for 5 minutes.

Scrape the sides and add the second egg, cold from the fridge. Mix for another 5 minutes on high speed. The mixture will be smooth and silky.

Spoon onto the top of the cooled brownies. Don't put on while the brownies are hot, it will melt the french silk. Smooth the top with a rubber spatula or offset spatula.

Place in refrigerator and allow to cool for at least 2 hours. Store in refrigerator covered.