Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking pan.

In a large saucepan, melt the 1 cup of butter over medium-low heat. Stir in the sugar until well combined, then remove from heat, letting it cool slightly.

Once cooled, whisk in the eggs one at a time, along with the vanilla, ensuring each egg is incorporated before adding the next.

In a separate bowl, sift together the flour, cocoa powder, and salt. Gradually fold this mixture into the butter mixture, being careful not to overmix.

Pour the brownie batter into the prepared pan, smoothing it out evenly.

Bake for about 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Allow the brownies to cool completely in the pan.

In a mixing bowl, beat the softened ½ cup of butter and sugar until light and fluffy.

Add in the eggs one at a time, beating for about five minutes after each addition until the mixture is thick and glossy.

Stir in the vanilla and melted chocolate until fully combined.

In another bowl, whip the heavy cream until soft peaks form, then gently fold it into the chocolate mixture until just combined.

Once the brownies have cooled, spread the French silk topping generously over the top.

Refrigerate for at least two hours to set.