Grease the pan with some butter. I use a 17 x 25 cm (6,5 x 10 inches), but it can be slightly smaller or bigger than that. Spread the roughly chopped walnuts on the bottom. Prepare the batter by beating the eggs with the sugar until fluffy. Add the flour and give the mixture a nice stir, until the flour is absorbed and the mixture is smooth. Simple apple walnut cakePeel the apples and slice them into 1 cm (1/3 inch) thick pieces. Arrange them over the walnuts and cover immediately with the batter, so the apples don’t get brown. Bake in preheated to 200C/390F oven, the rack set on medium level. The cake is ready when nicely browned, (or make the wooden stick test, if not sure). Leave it to cool in the tin for 10-15 minutes. Can be sliced when warm, but not steaming hot.