Preheat your oven to 180°C (350°F). Separate the eggs, whipping the egg whites until stiff peaks form. In another bowl, whisk the egg yolks with sugar until light and fluffy. Gradually fold in the flour and baking powder, then incorporate the whipped egg whites. Pour into a greased springform pan and bake for 20 minutes. Cool completely.

Prepare the pistachio mousse by grinding the roasted pistachios until finely chopped. Soak gelatin in water to bloom. Heat gently to dissolve, then mix with the ground pistachios, sugar, and whipped cream until combined. Spread over the cooled biscuit base and refrigerate for about 2 hours until set firm.

For the raspberry mousse, puree the raspberries and strain through a sieve. Soak gelatin in water as before, dissolve, then combine with raspberry puree and sugar. Fold into whipped cream until just combined. Spread over the set pistachio mousse layer.

Chill the tartlets in the fridge for another 2 hours until fully set. Remove from the springform pan and decorate with fresh raspberries, chopped pistachios, and mint leaves.