For the puff pastry slices raspberry vanilla defrost the puff pastry and raspberries according to the instructions on the package. For the vanilla foam, mix 250 ml whipped cream with granulated sugar and bring to a boil. Stir the custard powder with the milk until smooth and add to the hot whipped cream.
Whisk the remaining whipped cream into the thickened vanilla cream, pour the mixture into a whipped cream bottle, screw in a cartridge and chill for 1 – 2 hours.
Roll out puff pastry, cut into 12 squares and place on a baking sheet lined with baking paper, spacing them slightly apart. Brush the edges of the puff pastry squares with egg. Place an ovenproof coffee cup or glass in the center of each piece.
Bake in the preheated oven at 200°C (medium hot air) for 10 – 13 minutes until golden brown. Pour vanilla foam into the cavity of the cooled slices (lift the cups from the dough only after cooling), decorate with raspberries and serve the puff pastry slices sprinkled with powdered sugar.