Lay out the bottom of a springform pan (28 cm Ø) crosswise with 2 sheets of aluminium foil and place 3-4 cm high at the edge. Melt 40 g of fat and pour it evenly onto the bottom lined with aluminium foil. Sprinkle with 90 g sugar. Coarsely chop the walnut kernels and spread evenly on top
Peel, quarter and core the apples. Cut the apple quarters into slices, mix with lemon juice and 35 g sugar and spread on the walnuts
Cream 160 g fat, 200 g sugar, lemon zest and salt with the whisk of the hand mixer. Stir in the eggs one after the other. Mix flour and baking powder and finally stir in briefly. Spread the dough on the apples and smooth it down. Bake in the preheated oven, lower shelf (electric oven: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 1 hour. Cover at the end of the baking time if necessary
Remove the cake from the oven and let it cool in the mould on a cake rack. Turn the cake over onto an ovenproof plate, remove from the mould and remove the aluminium foil. Caramelise the walnut sugar crust with a small gas burner until golden brown (or caramelise under the preheated grill for about 3 minutes). Arrange the apple pie on a tart plate and dust with icing sugar as desired. Whipped cream tastes good with it