Start by preparing the crust. In a mixing bowl, combine the graham cracker crumbs, butter, and brown sugar. Stir until the mixture resembles wet sand. Press this mixture firmly into the bottom of 4 to 6 parfait glasses to create a solid base.
Next, take your frozen raspberries and push them through a sieve into a bowl to remove the seeds. The goal is to create a smooth raspberry puree. Once done, mix in the sugar until it's fully dissolved, creating a sweet raspberry sauce.
Now let's get to the egg whites. In a clean bowl, beat the egg whites until they are frothy and slightly thickened. This will add airiness to your mousse.
Gently fold the frothy egg whites into the raspberry mixture. Be careful not to deflate the egg whites; this lightness is critical for a fluffy mousse.
In a small microwave-safe bowl, combine the gelatin with 1 tablespoon of cold water. Stir it and let it sit for a minute, then microwave it for about 10 to 30 seconds until it liquefies. This step is essential for setting your mousse.
In another bowl, whip the whipping cream until it forms stiff peaks. This will create that luscious texture we all love in a mousse. Pour the melted gelatin into the whipped cream and mix gently to combine.
Now, carefully fold the raspberry mixture into the whipped cream. Use a spatula to combine gently, maintaining that airy texture.
Once everything is well combined, divide the raspberry mousse mixture evenly between the parfait glasses over the crust layer. Chill in the refrigerator for at least one hour to allow it to set properly.
When ready to serve, garnish the mousse with fresh raspberries or a dollop of whipped cream for a finishing touch. Enjoy your delightful Raspberry Mousse!
