For the crust: Crush the speculoos cookies and mix with the melted butter. Press the mixture evenly into a serving dish with a cake ring or springform pan. Chill in the refrigerator.

For the cream: Thaw the raspberries. Puree them, then strain through a fine mesh sieve to remove the seeds. Soak the gelatin in cold water. Heat the raspberry puree with the granulated sugar in a saucepan. Add the drained gelatin and stir to dissolve. Let cool. Whip the heavy cream until stiff peaks form. Add the powdered sugar and whip again. Gently fold the cooled raspberry puree into the whipped cream with a spatula.

For the mirror glaze: After 2 hours, prepare the glaze. Soak the gelatin in cold water. Puree the strawberries and strain through a fine mesh sieve. In a saucepan, heat the strawberry puree with the granulated sugar. Add the drained gelatin and stir until dissolved. Let cool, then pour over the top of the dessert. Chill for another 2 hours.