Prepare a 9-inch springform pan by lining the bottom with parchment paper and greasing the sides with butter.

In a medium saucepan, melt ½ cup of unsalted butter and 8 ounces of semi-sweet chocolate over low heat, stirring until smooth.

In a separate bowl, whisk together 3 large eggs and ¾ cup each of granulated and light brown sugar until frothy.

Mix the melted chocolate into the egg mixture, gently folding in ½ cup of all-purpose flour, ¼ cup of cocoa powder, and a pinch of salt.

Bake in the preheated oven at 350°F for 25–30 minutes, until a toothpick comes out mostly clean.

Allow the brownie to cool completely in the pan.

While the brownie base cools, prepare the raspberry mousse by blending 1 cup of fresh raspberries and straining to remove seeds.

Bloom 1 tablespoon of powdered gelatin in 2 tablespoons of cold water and heat gently until dissolved, mixing into the raspberry puree.

In a large mixing bowl, whip 1 cup of heavy whipping cream with ¼ cup of powdered sugar until stiff peaks form.

Gradually fold the raspberry mixture into the whipped cream until fully combined.

Pour the raspberry mousse evenly over the cooled brownie base and refrigerate for at least 4 hours.

To prepare the ganache, heat 1 cup of heavy whipping cream until steaming, remove from heat and mix with 8 ounces of chopped semi-sweet chocolate until smooth.

Allow the ganache to cool slightly before pouring it over the set mousse layer.

Let the ganache set for about 30 minutes before garnishing with fresh raspberries.

Gently run a knife along the edges of the pan before releasing the springform and serve chilled.