Peel and core the apples and cut into small cubes. Mix the apple cubes with cornflour, apple juice, lemon juice and grated tonka bean. Finely grate the ginger and add to the mixture. Leave the mixture to infuse for about 10 minutes.
For the dough, knead the wheat flour, pumpkin spice, baking sugar, chopped walnuts, cold butter, chopped pumpkin seeds, lemon zest and a pinch of salt into a crumbly dough. Grease a baking dish with butter and spread the apple pieces evenly in it. Crumble the dough into crumbles with your hands and sprinkle over the apples. Then top with the whole pumpkin seeds.
Bake at 180°C fan oven on the middle shelf for 30-40 minutes until the crumble is golden brown. Meanwhile, mix the crème fraiche with a little maple syrup and grated tonka bean and serve as a topping on the warm crumble.
Enjoy the taste!