For the apple-raisin muffins, preheat the oven to 200 degrees and line a muffin tin with paper cups for 12 pieces.
Mix flour with baking powder, baking soda, cardamom, nutmeg, 150 g sugar, vanilla sugar, 1 tsp cinnamon and salt in a bowl.
Sprinkle the sliced apples with lemon juice and mix with the raisins, half of the chopped nuts, 3 tablespoons of butter, milk and eggs.
Stir in the flour mixture and pour the batter into the molds. Mix the remaining butter with 1 tsp of cinnamon, the lemon zest, the remaining sugar and the remaining nuts and spread on the muffins.
Bake the apple-raisin muffins for about 20 to 25 minutes in the oven at 200 degrees.