01 -
Combine fresh raspberries and granulated sugar in a small saucepan over medium heat. Stir occasionally until berries release their juices and break down, about 5 to 7 minutes. Pass mixture through a fine mesh strainer to remove seeds, yielding a smooth puree. Stir in lemon juice if desired. Allow to cool completely.
02 -
For increased structure, sprinkle unflavored gelatin over cold water in a small bowl. Allow to bloom for 5 minutes, then microwave for 5 to 10 seconds until dissolved. Cool slightly. Blend melted gelatin into cooled raspberry puree and mix well.
03 -
In a large mixing bowl, combine chilled heavy whipping cream, powdered sugar, and vanilla extract. Whip using an electric mixer until stiff peaks form, ensuring not to overbeat.
04 -
Gently fold the raspberry puree into the whipped cream mixture in three additions, working carefully to maintain lightness and volume. If gelatin was added, the mixture will begin to firm as it is handled.
05 -
Divide mousse evenly among serving glasses or dessert bowls. Refrigerate for at least 2 hours to set and develop flavor. Garnish with reserved raspberries before serving.