Preheat the oven to 200 degrees. Mix the cream cheese with 1 egg, 50 g sugar and a packet of vanilla sugar. Heat the milk and butter in a saucepan until the butter has melted. Make sure that the mixture does not start to boil. Set aside and let cool.
Then stir in 2 eggs. In a bowl, mix the flour, baking powder, baking soda, salt, 1 packet of vanilla sugar and the remaining sugar. Add the milk, butter and egg mixture and stir until the dough is nice and smooth. Then stir in the frozen berries.
Grease a muffin baking pan and dust with flour or breadcrumbs (this will prevent the muffins from sticking). Spread the dough in the wells and then spread the cream cheese on top. Bake in the middle of the oven for about 25 minutes.