For the apples, peel the apples and boil with the sugar, calvados, lemon juice, and 150 ml (approximately ¾ cup) of water. Simmer 5-10 minutes, apples should not get too soft. Drain and allow to cool.
Line the wells of a muffin tray with paper cases.
For the muffins, beat the butter until creamy. Add the sugar and vanilla sugar and gradually stir in the eggs. Add the cream and mix well.
Mix the flour with baking powder and sift. Add the flour mixture to the egg mixture and mix quickly into a smooth batter. Pour the batter into the lined wells of muffin tray. Bake in a preheated oven at 175°C (fan: 155°C, gas mark 2-3) (approximately 350°F) for about 10 minutes. Press a little apple in the middle of each cake and bake for another 5-10 minutes.
Remove the muffins from the baking tray and allow to cool.
Serve to taste with strawberry sauce.