- 20 minutes
- 30 minutes (plus cooling time)
- For the cake, preheat the oven to 375°F. Generously grease a 10-inch springform pan with butter, and line the bottom and sides with parchment paper. Beat the cake mix, water, eggs and oil in a large bowl until smooth, using a hand mixer.
- Pour the batter into the prepared pan and bake until a toothpick inserted into the center comes out clean, about 25-30 minutes. Let cool completely at room temperature, about 1 hour, before topping with the mousse.
- For the mousse, place the raspberries in a food processor or blender and puree until smooth. Strain through a fine mesh sieve and discard the seeds. Transfer the puree to a large bowl. Stir in the sugar and set aside.
- Stir the gelatin and water together in a small bowl until dissolved. Add the gelatin mixture to the raspberry puree and stir to combine. Beat the raspberry mixture and heavy whipping cream until light and fluffy, using a hand mixer, about 2-4 minutes.
- Spoon the mousse in an even layer over the cooled cake. Cover with plastic wrap and refrigerate for 1-2 hours until set.
- Carefully unmold the cake from the springform pan. Top with the whipped topping and raspberries and enjoy.
Recipe Tip: Substitute blackberries or quartered strawberries for the raspberries to create a different fruit mousse!