Finely grind the peanuts. Melt the butter and mix with the caramel. Mix the peanuts with baking powder and add sugar, vanilla sugar, salt and eggs. Add the butter and caramel mixture and stir everything well.
Grease a 26 springform pan. Pour in the dough and bake at 160 ° C for about 40 minutes.
Tip for making caramel: Boil sweetened condensed milk in the sealed can in water for 2 hours. The can must always be completely covered with water. Let the can cool down completely before opening it. Can be made well in advance.