01 - Puree raspberries with sugar and lemon juice in blender until smooth. Strain through fine sieve to remove seeds. Set aside.
02 - Soak gelatin sheets in cold water for 5 minutes, or sprinkle powdered gelatin over 2 tbsp cold water to bloom.
03 - Gently heat 2 tbsp raspberry puree in small saucepan until warm. Squeeze water from gelatin sheets and stir into warm puree (or stir bloomed powdered gelatin until dissolved). Mix back into remaining puree. Cool to room temperature.
04 - Whip heavy cream with vanilla in clean bowl until medium peaks form. Refrigerate until needed.
05 - Whisk egg whites to soft peaks, then gradually add powdered sugar and whip to stiff peaks.
06 - Gently fold raspberry puree into whipped cream until almost combined. Carefully fold in meringue until smooth and fully incorporated.
07 - Spoon or pipe mixture into serving glasses. Chill for at least 2 hours until set.
08 - Garnish with fresh raspberries and optionally dust with powdered sugar or add mint leaves before serving.