Royal Eton Mess

To Make the Raspberry Puree: Combine 4 oz of Raspberries, 2 tbsp Powdered Sugar and a few drops of Lemon Juice into a blender. Blend until liquid and use a strainer to rid the seeds. Set aside.
Preheat oven 350. Line two baking trays with non stick parchment paper.
Make meringues: in a dry clean bowl, whisk egg whites and cream of tartar to stiff peaks (glossy and stand in firm peaks). Gradually add all the sugar, whisking continuously. Continue for about 5 minutes until the mixture is very thick and stands up on it's own. Add vanilla extract. Using a piping bag, use a medium nozzle and pipe small meringues (or different sized discs). Bake for 1-1/2 hours. When cooked, they will be firm and crisp, and will easily lift off the parchment. Check them after 1 hour, and cook for longer if required. When cooked, turn off oven but leave meringues in to dry out further.
Wash, dry and prepare all the berry fruits.
Whip the cream until thick, and then stir in the mascarpone, sugar, and chopped mint.
To Assemble: Layer up the fruit and the cream alternately with the meringues and a drizzle of the raspberry puree, finishing with cream and then fruit. Garnish with mint leaves, and complete the dish with a dusting of powdered sugar just before serving.