Soak raisins in rum overnight. If you are short of time, warm the rum (do not boil) and soak the raisins for a couple of hours. The raisins should plump nicely as they absorb some of the liquid. Drain and reserve the left rum.
Core, seed, and chop the apples. Do not peel them. In a medium saucepan over medium heat, add the chopped apples, granulated sugar, allspice, ground cardamom, 2 tablespoons of water, lemon slice, and what is left from the rum. Let it frequently cook until the liquid evaporates, about 10 minutes. Remove from stove, fish out the lemon slice, and discard it. Add raisins and stir to combine. Let it cool to room temperature.
Preheat the oven to 400F (204C). Break along pre-scored lines to separate the puffy pastry shells—place shells on ungreased baking sheets with “tops” up. Place the baking sheet in the middle of the oven rack. Bake it for 15 minutes or until golden brown and puffed.
Cool on a wire rack for 5 minutes. Use a sharp knife to carefully remove the “tops” and soft pastry underneath, leaving a central cavity. Let them cool completely, about 15 minutes. Using a small spoon, fill the baskets with apples. Dust the baskets with powdered sugar.