Preheat oven to 180 degrees C. Line a muffin tin with 12 paper baking cups.
Combine flour, sugar, baking powder, bicarb soda and salt. In another bowl mix butter, eggs, apple and vanilla. Mix in the flour mixture and stir until well combined then stir in the caramel condensed milk, to taste.
Spoon into the lined muffin cups. Bake in the preheated oven until a knife inserted in the centre comes out clean, about 30 minutes. Allow to cool on a wire rack before icing.
Beat together cream cheese, butter and vanilla until well mixed. Slowly beat in the icing sugar. Beat in the caramel condensed milk until desired sweetness is reached. Pipe onto cooled cupcakes.