1. Prepare the Brownie Base:

• Preheat your oven to 350°F (175°C). Grease and line a 9-inch (23cm) round cake pan with parchment paper.
• In a mixing bowl, combine sugar and melted butter. Add the eggs and mix until well combined.
• Sift in flour and cocoa powder, stirring until the batter is smooth.
• Pour the batter into the prepared cake pan and bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
• Allow the brownie to cool completely in the pan.

2. Prepare the Raspberry Mousse:

• In a small bowl, sprinkle gelatin over water and let it bloom for 5 minutes.
• In a saucepan, heat the raspberry puree and sugar over low heat until the sugar dissolves. Remove from heat and stir in the bloomed gelatin until fully dissolved.
• Let the mixture cool to room temperature.
• In a separate bowl, whip the heavy cream until stiff peaks form.
• Gently fold the cooled raspberry mixture into the whipped cream until well combined.

3. Assemble the Cake:

• Once the brownie base has cooled, remove it from the cake pan and place it on a serving platter.
• Spread the raspberry mousse evenly over the brownie base.
• Refrigerate the assembled cake for at least 4 hours, or until the mousse is fully set.