• Beat the softened butter with the sugar, grated lemon zest, cinnamon, rum and salt until creamy.
• Beat the eggs and stir in gradually.
• Peel the apples, grate coarsely and wring out thoroughly.
• Mix the chopped walnuts thoroughly with the wheat flour and baking powder and stir in gently with the grated apples to the butter mixture.

Final phase

• Sprinkle the mould with almond slivers, pour in the mixture, and bake in a preheated oven for about 1 hour at about 170°C.
• Allow the cake to cool slightly in the pan, invert onto a wire rack and allow to cool completely.
• Dust the tart with icing sugar and serve.